Create initial message schemas

Closes #7 (closed)

examples/ecosub_c2/platform_status.json

     "longitude": -10.122,
     "depth": 50,
     "altitude": 20,
+    "heading": 90.0,
     "health_status": "Warning",
     "localisation_error": null,
     "usbl_fix_seconds_ago": null,

examples/hydrosurv_adapter/platform_status.json

   "active": true,
   "status_source": "onboard_platform",
   "battery_remaining_capacity": 80.2,
+  "heading": 310.0,
   "health_status": "Lost Connection",
   "latitude": 178.2,
   "longitude": -10.122,

formats/planning_configuration.py

         "safe_command": {
             "type": "string",
             "enum": ["go_home", "abort_now", "stop_mission"],
-            "description": "Command/Action that is native to respective partner's platform/C2",
+            "description": "Command/Action that is native to respective"
+            + " partner's platform/C2",
             "example": "go_home",
         },
         "latitude_waypoint": {
             "type": "number",
-            "description": "X-coordinate of safe place for respective platform",
+            "description": "X-coordinate safe place for respective platform",
             "example": -7.432,
         },
         "longitude_waypoint": {
             "type": "number",
-            "description": "Y-coordinate of safe place for respective platform",
+            "description": "Y-coordinate safe place for respective platform",
             "example": 50.365,
         },
         "target_depth": {
             "type": "number",
-            "description": "Z-coordinate of safe place for respective platform"
+            "description": "Z-coordinate safe place for respective platform"
             + " . If platform to NOT stay at depth, key in `0.0`",
             "example": 10,
         },
             "example": {"swath_width": 10.0, "scan_type": "DVL"},
         },
     },
-    "required": ["platform_ID", "serial", "model", "emergency", "min_altitude", "min_velocity", "max_velocity"],
+    "required": [
+        "platform_ID",
+        "serial",
+        "model",
+        "emergency",
+        "min_altitude",
+        "min_velocity",
+        "max_velocity",
+    ],
 }
 
 region_schema = {

formats/platform_status.py

             "description": "TODO: Needs further consideration",
             "example": 124.3,
         },
+        "heading": {
+            "type": "number",
+            "description": "Angular distance relative to north, usually 000°"
+            + " at north, clockwise through 359°, in degrees",
+            "example": 124.3,
+        },
         "health_status": {
             "type": "string",
             "description": "Health status extracted by respective platform "

generate_swagger.py

                             "schema": {
                                 "allOf": [
                                     {
-                                        "$ref": "#/components/schemas"
-                                        + "/" + item,
+                                        "$ref": "#/components/schemas/" + item,
                                     },
                                 ],
                                 "discriminator": {