Draft-06/7 don't allow empty enums (#876)

Author: jdesrosiers

tests/draft6/enum.json

@@ -316,41 +316,5 @@
                 "valid": false
             }
         ]
-    },
-    {
-        "description": "empty enum",
-        "schema": {"enum": []},
-        "tests": [
-            {
-                "description": "string is invalid",
-                "data": "foo",
-                "valid": false
-            },
-            {
-                "description": "number is invalid",
-                "data": 42,
-                "valid": false
-            },
-            {
-                "description": "null is invalid",
-                "data": null,
-                "valid": false
-            },
-            {
-                "description": "object is invalid",
-                "data": {},
-                "valid": false
-            },
-            {
-                "description": "array is invalid",
-                "data": [],
-                "valid": false
-            },
-            {
-                "description": "boolean is invalid",
-                "data": false,
-                "valid": false
-            }
-        ]
     }
 ]

tests/draft7/enum.json

@@ -316,41 +316,5 @@
                 "valid": false
             }
         ]
-    },
-    {
-        "description": "empty enum",
-        "schema": {"enum": []},
-        "tests": [
-            {
-                "description": "string is invalid",
-                "data": "foo",
-                "valid": false
-            },
-            {
-                "description": "number is invalid",
-                "data": 42,
-                "valid": false
-            },
-            {
-                "description": "null is invalid",
-                "data": null,
-                "valid": false
-            },
-            {
-                "description": "object is invalid",
-                "data": {},
-                "valid": false
-            },
-            {
-                "description": "array is invalid",
-                "data": [],
-                "valid": false
-            },
-            {
-                "description": "boolean is invalid",
-                "data": false,
-                "valid": false
-            }
-        ]
     }
 ]