avocado.utils.remote: Log when module is disabled.

Log message if remote or virt module is off.
Signed-off-by: NRuda Moura <rmoura@redhat.com>

avocado/utils/remote.py

@@ -17,12 +17,16 @@ Module to provide remote operations.
 """
 
 import getpass
+import logging
+
+log = logging.getLogger('avocado.test')
 
 try:
     import fabric.api
     import fabric.operations
 except ImportError:
     remote_capable = False
+    log.info('Remote module is disabled: could not import fabric')
 else:
     remote_capable = True
 

avocado/utils/virt.py

@@ -16,10 +16,15 @@
 Module to provide classes for Virtual Machines.
 """
 
+import logging
+
+log = logging.getLogger('avocado.test')
+
 try:
     import libvirt
 except ImportError:
     virt_capable = False
+    log.info('Virt module is disabled: could not import libvirt')
 else:
     virt_capable = True
 
@@ -28,6 +33,7 @@ from avocado.utils import remote
 
 if remote.remote_capable is False:
     virt_capable = False
+    log.info('Virt module is disabled: remote module is disabled')
 
 
 class Hypervisor(object):