Job Submission CLI (#122)

* Initial commit of job submission cli tool, with minor fixes in API code

* Refactored and further decoupled server / client code

* Clean up ServerProxy to not use hardcoded loopback addresses

src/api/api_server.py

@@ -34,7 +34,7 @@ ssl._create_default_https_context = ssl._create_unverified_context  # disable SS
 
 API_VERSION = "1"
 
-def start_server(hostname=None):
+def start_api_server(hostname=None):
 
     # get hostname
     if not hostname:
@@ -463,6 +463,10 @@ def get_renderer_help(renderer):
 # --------------------------------------------
 # Miscellaneous:
 # --------------------------------------------
+@server.get('/api/heartbeat')
+def heartbeat():
+    return datetime.now().isoformat(), 200
+
 @server.post('/api/job/<job_id>/send_subjob_update_notification')
 def subjob_update_notification(job_id):
     subjob_details = request.json