Remove some duplication in the required fields for parallel and events states (#366)

Signed-off-by: Jorgen Johnson <[email protected]>

Author: jorgenj

schema/workflow.json

@@ -663,14 +663,6 @@
             "onEvents",
             "transition"
           ]
-        },
-        {
-          "required": [
-            "name",
-            "type",
-            "onEvents",
-            "end"
-          ]
         }
       ]
     },
@@ -900,14 +892,6 @@
               "branches",
               "transition"
             ]
-          },
-          {
-            "required": [
-              "name",
-              "type",
-              "branches",
-              "end"
-            ]
           }
         ]
       }