Fix docker labels (frontend.*)

Using Docker provider, you can specify `traefik.frontend.rule` and
`traefik.frontend.value` labels. If they are not both provided, there is
a default behavior. On the current master, if they are not defined, the
container is filtered (and thus the default behavior is broken).

Fixes that.

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

integration/integration_test.go

@@ -41,17 +41,6 @@ func (s *FileSuite) SetUpSuite(c *check.C) {
 	s.composeProject.Up()
 }
 
-// Docker test suites
-type DockerSuite struct{ BaseSuite }
-
-func (s *DockerSuite) SetUpSuite(c *check.C) {
-	// Make sure we can speak to docker
-}
-
-func (s *DockerSuite) TearDownSuite(c *check.C) {
-	// Clean the mess
-}
-
 // Consul test suites (using libcompose)
 type ConsulSuite struct{ BaseSuite }