gpperfmon: add behave test for running

-- add README for macOS build and configuration notes
Signed-off-by: NLarry Hamel <lhamel@pivotal.io>

gpAux/gpperfmon/README.md

+# Libraries Required
+## libsigar:
+	https://github.com/hyperic/sigar
+	For macOS:
+		to build:
+	    `mkdir build && cd build && cmake .. && make && make install`
+# Troubleshoot
+	For macOS:
+		You may hit a reverse look up issue when viewing the logs of gpperfmon by default $MASTER_DATA_DIRECTORY/gpperfmon/logs
+```
+	2017-04-11 14:59:56.821681
+	PDT,"gpmon","gpperfmon",p40501,th-1633193024,"::1","54006",2017-04-11 14:59:56
+	PDT,0,con5,,seg-1,,,,sx1,"FATAL","28000","no pg_hba.conf entry for host
+	""::1"", user ""gpmon"", database ""gpperfmon""",,,,,,,0,,"auth.c",608, ```
+```
+	And also issues at $MASTER_DATA_DIRECTORY/pg_log:
+```
+		Performance Monitor - failed to connect to gpperfmon database: could not connect to server: No such file or directory
+	Is the server running locally and accepting
+	connections on Unix domain socket ""/var/pgsql_socket/.s.PGSQL.15432""?",,,,,,,,"SysLoggerMain","syslogger.c",618,
+```
+		to get pass this you need to do 2 things:
+			1) export PGHOST=foo  # where 'foo' is your hostname that is NOT localhost
+			2) sudo /etc/hosts   # and separate out (re)definitions of 127.0.0.1, something like:
+				127.0.0.1	foo
+				127.0.0.1	localhost
+

gpMgmt/test/behave/mgmt_utils/gpperfmon.feature

@@ -5,12 +5,29 @@ Feature: gpperfmon
     Scenario: install gpperfmon
         Given the database "gpperfmon" does not exist
         When the user runs "gpperfmon_install --port 15432 --enable --password foo"
-#        # enable the following to verify the role
-#        And the user runs "gpstop -ar"
-#        Then verify that a role "gpmon" exists in database "gpperfmon"
+        Then gpperfmon_install should return a return code of 0
         Then verify that the last line of the master postgres configuration file contains the string "gpperfmon_log_alert_level=warning"
         And verify that there is a "heap" table "database_history" in "gpperfmon"
 
+    @gpperfmon_run
+    Scenario: run gpperfmon
+        # important: to succeed on macOS, see steps in gpdb/gpAux/gpperfmon/README
+        Given the database "gpperfmon" does not exist
+        When the user runs "gpperfmon_install --port 15432 --enable --password foo"
+        Then gpperfmon_install should return a return code of 0
+        When the user runs command "pkill postgres"
+        And waiting "5" seconds
+        And the user runs "gpstart -a"
+        Then gpstart should return a return code of 0
+        Then verify that a role "gpmon" exists in database "gpperfmon"
+        Then verify that the last line of the master postgres configuration file contains the string "gpperfmon_log_alert_level=warning"
+        And verify that there is a "heap" table "database_history" in "gpperfmon"
+        When the user runs command "pgrep gpmmon"
+        Then pgrep should return a return code of 0
+        When waiting "5" seconds
+        When the user runs command "pgrep gpsmon"
+        Then pgrep should return a return code of 0
+
 #    todo this test may have never run. Is it valid? Worthy of fixing?
 #    Scenario: drop old partition
 #        When the user runs command "echo 'partition_age = 4' >> $MASTER_DATA_DIRECTORY/gpperfmon/conf/gpperfmon.conf"