Support combination of shorthand flag and equal sign for host option

Signed-off-by: Joffrey F <joffrey@docker.com>

compose/cli/command.py

@@ -21,12 +21,15 @@ log = logging.getLogger(__name__)
 
 def project_from_options(project_dir, options):
     environment = Environment.from_env_file(project_dir)
+    host = options.get('--host')
+    if host is not None:
+        host = host.lstrip('=')
     return get_project(
         project_dir,
         get_config_path_from_options(project_dir, options, environment),
         project_name=options.get('--project-name'),
         verbose=options.get('--verbose'),
-        host=options.get('--host'),
+        host=host,
         tls_config=tls_config_from_options(options),
         environment=environment
     )

tests/acceptance/cli_test.py

@@ -145,6 +145,13 @@ class CLITestCase(DockerClientTestCase):
         # Prevent tearDown from trying to create a project
         self.base_dir = None
 
+    def test_shorthand_host_opt(self):
+        self.dispatch(
+            ['-H={0}'.format(os.environ.get('DOCKER_HOST', 'unix://')),
+             'up', '-d'],
+            returncode=0
+        )
+
     def test_config_list_services(self):
         self.base_dir = 'tests/fixtures/v2-full'
         result = self.dispatch(['config', '--services'])