Fix "End of file during parsing" when no errors with tslint #981
Ping @Simplify since you seem to be responsible for the tslint integration. Thanks, by the way!
When outputting to JSON format, tslint returns nothing
This patch replaces empty string with a valid empty JSON object,
When outputting to JSON format, tslint returns nothing (empty string) if there are no errors. Passing empty string to json-read-from-string throws an "End of file during parsing" error. This patch sets the intermediate variable to nil instead of throwing an error, which allows the Flycheck pass to complete normally.