typing: Convert function type annotations to Python 3 style.

Generated by com2ann (slightly patched to avoid also converting
assignment type annotations, which require Python 3.6), followed by
some manual whitespace adjustment, and two fixes for use-before-define
issues:

-    def set_zulip_client(self, zulipToJabberClient: ZulipToJabberBot) -> None:
+    def set_zulip_client(self, zulipToJabberClient: 'ZulipToJabberBot') -> None:

-def init_from_options(options: Any, client: Optional[str] = None) -> Client:
+def init_from_options(options: Any, client: Optional[str] = None) -> 'Client':

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

zulip/integrations/openshift/post_deploy

@@ -21,8 +21,7 @@ client = zulip.Client(
     api_key=config.ZULIP_API_KEY,
     client='ZulipOpenShift/' + VERSION)
 
-def get_deployment_details():
-    # type: () -> Dict[str, str]
+def get_deployment_details() -> Dict[str, str]:
     # "gear deployments" output example:
     #   Activation time - Deployment ID - Git Ref - Git SHA1
     #   2017-01-07 15:40:30 -0500 - 9e2b7143 - master - b9ce57c - ACTIVE
@@ -34,8 +33,7 @@ def get_deployment_details():
                 branch=splits[2],
                 commit_id=splits[3])
 
-def send_bot_message(deployment):
-    # type: (Dict[str, str]) -> None
+def send_bot_message(deployment: Dict[str, str]) -> None:
     destination = config.deployment_notice_destination(deployment['branch'])
     if destination is None:
         # No message should be sent