Add etc/*.conf files to .gitignore

This commit makes etc/*.conf files be ignored from git repo. We don't
need to track user configuration files not only tempest.conf but also
the others such as custom-tempest.conf.

Change-Id: I46b3828426a37291205812bf377e7eeece9b7e0b

.gitignore

@@ -3,9 +3,8 @@ ChangeLog
 *.pyc
 __pycache__/
 etc/accounts.yaml
-etc/tempest.conf
+etc/*.conf
 etc/tempest.conf.sample
-etc/logging.conf
 include/swift_objects/swift_small
 include/swift_objects/swift_medium
 include/swift_objects/swift_large