Add app.wsgi to target of pep8

The app.wsgi file should be adjusted to meet pep8 standards and
apply pep8 check to app.wsgi automatically.

Change-Id: I34ec9ce56a329ede76d3d69f6e973d66350d85d1

tox.ini

@@ -47,6 +47,7 @@ commands =
     oslo-config-generator --config-file etc/watcher/oslo-config-generator/watcher.conf
 
 [flake8]
+filename = *.py,app.wsgi
 show-source=True
 ignore= H105,E123,E226,N320,H202
 builtins= _

watcher/api/app.wsgi

@@ -37,4 +37,3 @@ LOG.debug("Configuration:")
 CONF.log_opt_values(LOG, log.DEBUG)
 
 application = app.VersionSelectorApplication()
-