Fix Bower warnings

[btoone]

Looks like you forgot to bump the bower.json file. This patch fixes the "mismatch" warning and also adds the "ignore" entry to fix the "invalid-meta" property.

Just a little fix but I hope it makes your job as a maintainer a bit easier. Thanks for the great library.

bower info underscore.string
bower underscore.string#*       cached git://github.com/epeli/underscore.string.git#2.3.3
bower underscore.string#*     validate 2.3.3 against git://github.com/epeli/underscore.string.git#*
bower underscore.string#*          new version for git://github.com/epeli/underscore.string.git#*
bower underscore.string#*      resolve git://github.com/epeli/underscore.string.git#*
bower underscore.string#*     download https://github.com/epeli/underscore.string/archive/3.0.0.tar.gz
bower underscore.string#*      extract archive.tar.gz
bower underscore.string#*     mismatch Version declared in the json (2.4.0) is different than the resolved one (3.0.0)
bower underscore.string#* invalid-meta underscore.string is missing "ignore" entry in bower.json
bower underscore.string#*     resolved git://github.com/epeli/underscore.string.git#3.0.0

[stoeffel]

Thanks. I will have to add the bower.json in the gulpfile.