Remove redundant oneOf definitions

For simple definitions where a field can be multiple types, we can
specify the allowed types in an array. It's simpler and clearer.

This is only applicable to *simple* definitions, like number, string, list,
object without any other constraints.

Signed-off-by: Mazz Mosley <mazz@houseofmnowster.com>

compose/config/fields_schema.json

@@ -24,12 +24,7 @@
           ]
         },
         "container_name": {"type": "string"},
-        "cpu_shares": {
-          "oneOf": [
-            {"type": "number"},
-            {"type": "string"}
-          ]
-        },
+        "cpu_shares": {"type": ["number", "string"]},
         "cpuset": {"type": "string"},
         "devices": {"type": "array", "items": {"type": "string"}, "uniqueItems": true},
         "dns": {"$ref": "#/definitions/string_or_list"},
@@ -74,18 +69,8 @@
         "log_opt": {"type": "object"},
 
         "mac_address": {"type": "string"},
-        "mem_limit": {
-          "oneOf": [
-            {"type": "number"},
-            {"type": "string"}
-          ]
-        },
-        "memswap_limit": {
-          "oneOf": [
-            {"type": "number"},
-            {"type": "string"}
-          ]
-        },
+        "mem_limit": {"type": ["number", "string"]},
+        "memswap_limit": {"type": ["number", "string"]},
         "name": {"type": "string"},
         "net": {"type": "string"},
         "pid": {"type": ["string", "null"]},