chore(package): update mocha to version 3.1.0 (#525)
chore(package): update mocha to version 3.1.0 (#525)

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shubheksha/web-ext,rpl/web-ext,mozilla/web-ext,shubheksha/web-ext,mozilla/web-ext,rpl/web-ext,kumar303/web-ext,kumar303/web-ext