build: Update karma to 1.5.0, karma-firefox-launcher to 1.0.1

build: Update karma to 1.5.0, karma-firefox-launcher to 1.0.1

karma:
 Changelog at https://github.com/karma-runner/karma/releases
 https://github.com/karma-runner/karma/compare/v1.1.0...v1.5.0

karma-firefox-launcher:
 Changelog at https://github.com/karma-runner/karma-firefox-launcher/blob/master/CHANGELOG.md#101-2017-03-04
 https://github.com/karma-runner/karma-firefox-launcher/compare/v1.0.0...v1.0.1

Karma v1.1.1 added use of `<script crossorigin="anonymous">` for
the urls it initially loads. While most requests will be done by
MW itself directly (and served locally via the proxy at /w/) the
initial request cannot come from the proxy and is loaded from wgServer
directly. Therefore we need to set crossOriginAttribute=false to override
the new default that v1.1.1 introduced.

Change-Id: I9f5067b949c0a77e46f47c2a110a7b5df5953fda