Prepare 0.5.3 release

package.json

@@ -1,7 +1,7 @@
 {
   "name": "atom-cfn-lint",
   "main": "./lib/atom-cfn-lint",
-  "version": "0.5.2",
+  "version": "0.5.3",
   "description": "Validate CloudFormation yaml/json templates against the CloudFormation spec and additional checks. Includes checking valid values for resource properties and best practices.",
   "keywords": [
     "linter",