Fix json schemas

config/schemas/bonus.json

@@ -3,7 +3,7 @@
 	"$schema" : "http://json-schema.org/draft-04/schema",
 	"title" : "VCMI bonus type format",
 	"description" : "Definition of bonus types",
-	"required" : ["type"],
+	"required" : [],
 	"additionalProperties" : false,
 	"properties" : {
 		"hidden" : {

config/schemas/spell.json

@@ -197,12 +197,8 @@
 		"school" : {
 			"type" : "object",
 			"description" : "List of spell schools this spell belongs to",
-			"additionalProperties" : false,
-			"properties" : {
-				"air" : {"type" : "boolean"},
-				"fire" : {"type" : "boolean"},
-				"earth" : {"type" : "boolean"},
-				"water" : {"type" : "boolean"}
+			"additionalProperties" : {
+				"type" : "boolean"
 			}
 		},
 		"level" : {