Add grunt-jsonlint and grunt-banana-checker

Authored by Umherirrender on Mar 20 2017, 7:24 PM.

Description

Add grunt-jsonlint and grunt-banana-checker

jsonlint and banana-checker will test for valid i18n files

Bug: T94547
Change-Id: I2578367051b807025af40b3a8f8deded147b13a5