docs: remove mentions of tagged_name test property

During the implementation of test ids (5973e898) some references to the
tagged name of a test were left in the docs.

Let's remove them for good.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

docs/source/WritingTests.rst

@@ -228,27 +228,27 @@ clear stages on a single test::
             # Preparing soil
             for row in range(rows):
                 progress_log.info("%s: preparing soil on row %s",
-                                  self.tagged_name, row)
+                                  self.name, row)
 
             # Letting soil rest
             progress_log.info("%s: letting soil rest before throwing seeds",
-                              self.tagged_name)
+                              self.name)
             time.sleep(2)
 
             # Throwing seeds
             for row in range(rows):
                 progress_log.info("%s: throwing seeds on row %s",
-                                  self.tagged_name, row)
+                                  self.name, row)
 
             # Let them grow
             progress_log.info("%s: waiting for Avocados to grow",
-                              self.tagged_name)
+                              self.name)
             time.sleep(5)
 
             # Harvest them
             for row in range(rows):
                 progress_log.info("%s: harvesting organic avocados on row %s",
-                                  self.tagged_name, row)
+                                  self.name, row)
 
 
 From this point on, you can ask Avocado to show your logging stream, either
@@ -261,18 +261,18 @@ The outcome should be similar to::
     JOB ID     : af786f86db530bff26cd6a92c36e99bedcdca95b
     JOB LOG    : /home/cleber/avocado/job-results/job-2016-03-18T10.29-af786f8/job.log
     TESTS      : 1
-     (1/1) plant.py:Plant.test_plant_organic:  progress: plant.py:Plant.test_plant_organic: preparing soil on row 0
-    progress: plant.py:Plant.test_plant_organic: preparing soil on row 1
-    progress: plant.py:Plant.test_plant_organic: preparing soil on row 2
-    progress: plant.py:Plant.test_plant_organic: letting soil rest before throwing seeds
-    -progress: plant.py:Plant.test_plant_organic: throwing seeds on row 0
-    progress: plant.py:Plant.test_plant_organic: throwing seeds on row 1
-    progress: plant.py:Plant.test_plant_organic: throwing seeds on row 2
-    progress: plant.py:Plant.test_plant_organic: waiting for Avocados to grow
-    \progress: plant.py:Plant.test_plant_organic: harvesting organic avocados on row 0
-    progress: plant.py:Plant.test_plant_organic: harvesting organic avocados on row 1
-    progress: plant.py:Plant.test_plant_organic: harvesting organic avocados on row 2
-    PASS
+     (1/1) plant.py:Plant.test_plant_organic: progress: 1-plant.py:Plant.test_plant_organic: preparing soil on row 0
+    progress: 1-plant.py:Plant.test_plant_organic: preparing soil on row 1
+    progress: 1-plant.py:Plant.test_plant_organic: preparing soil on row 2
+    progress: 1-plant.py:Plant.test_plant_organic: letting soil rest before throwing seeds
+    -progress: 1-plant.py:Plant.test_plant_organic: throwing seeds on row 0
+    progress: 1-plant.py:Plant.test_plant_organic: throwing seeds on row 1
+    progress: 1-plant.py:Plant.test_plant_organic: throwing seeds on row 2
+    progress: 1-plant.py:Plant.test_plant_organic: waiting for Avocados to grow
+    \progress: 1-plant.py:Plant.test_plant_organic: harvesting organic avocados on row 0
+    progress: 1-plant.py:Plant.test_plant_organic: harvesting organic avocados on row 1
+    progress: 1-plant.py:Plant.test_plant_organic: harvesting organic avocados on row 2
+    PASS (7.01 s)
     RESULTS    : PASS 1 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0
     JOB HTML   : /home/cleber/avocado/job-results/job-2016-03-18T10.29-af786f8/html/results.html
     TESTS TIME : 7.01 s
@@ -289,21 +289,21 @@ will be another log file named ``progress.INFO`` at the job results
 dir. During the test run, one could watch the progress with::
 
     $ tail -f ~/avocado/job-results/latest/progress.INFO
-    10:36:59 INFO | plant.py:Plant.test_plant_organic: preparing soil on row 0
-    10:36:59 INFO | plant.py:Plant.test_plant_organic: preparing soil on row 1
-    10:36:59 INFO | plant.py:Plant.test_plant_organic: preparing soil on row 2
-    10:36:59 INFO | plant.py:Plant.test_plant_organic: letting soil rest before throwing seeds
-    10:37:01 INFO | plant.py:Plant.test_plant_organic: throwing seeds on row 0
-    10:37:01 INFO | plant.py:Plant.test_plant_organic: throwing seeds on row 1
-    10:37:01 INFO | plant.py:Plant.test_plant_organic: throwing seeds on row 2
-    10:37:01 INFO | plant.py:Plant.test_plant_organic: waiting for Avocados to grow
-    10:37:06 INFO | plant.py:Plant.test_plant_organic: harvesting organic avocados on row 0
-    10:37:06 INFO | plant.py:Plant.test_plant_organic: harvesting organic avocados on row 1
-    10:37:06 INFO | plant.py:Plant.test_plant_organic: harvesting organic avocados on row 2
+    10:36:59 INFO | 1-plant.py:Plant.test_plant_organic: preparing soil on row 0
+    10:36:59 INFO | 1-plant.py:Plant.test_plant_organic: preparing soil on row 1
+    10:36:59 INFO | 1-plant.py:Plant.test_plant_organic: preparing soil on row 2
+    10:36:59 INFO | 1-plant.py:Plant.test_plant_organic: letting soil rest before throwing seeds
+    10:37:01 INFO | 1-plant.py:Plant.test_plant_organic: throwing seeds on row 0
+    10:37:01 INFO | 1-plant.py:Plant.test_plant_organic: throwing seeds on row 1
+    10:37:01 INFO | 1-plant.py:Plant.test_plant_organic: throwing seeds on row 2
+    10:37:01 INFO | 1-plant.py:Plant.test_plant_organic: waiting for Avocados to grow
+    10:37:06 INFO | 1-plant.py:Plant.test_plant_organic: harvesting organic avocados on row 0
+    10:37:06 INFO | 1-plant.py:Plant.test_plant_organic: harvesting organic avocados on row 1
+    10:37:06 INFO | 1-plant.py:Plant.test_plant_organic: harvesting organic avocados on row 2
 
 The very same ``progress`` logger, could be used across multiple test methods
-and across multiple test modules.  In the example given, the tagged test name
-is used to give extra context.
+and across multiple test modules.  In the example given, the test name is used
+to give extra context.
 
 :class:`unittest.TestCase` heritage
 ===================================