Remove version field (didn't exist until v1.1)

Author: josee-sabourin

system_regions.json

@@ -14,19 +14,6 @@
       "type": "integer",
       "minimum": 0
     },
-    "version": {
-      "description": "GBFS version number to which the feed conforms, according to the versioning framework.",
-      "type": "string",
-      "enum": [
-        "1.1-RC",
-        "1.1",
-        "2.0-RC",
-        "2.0",
-        "2.1-RC",
-        "2.1-RC2",
-        "3.0-RC"
-      ]
-    },
     "data": {
       "type": "object",
       "properties": {
@@ -57,7 +44,6 @@
   "required": [
     "last_updated",
     "ttl",
-    "version",
     "data"
   ]
 }