This gives us the capability to test the client-side JS
rewriting against a suite of different browsers on different
platforms.
Note that getting Karma running on Travis CI requires some
additional configuration documented at
github.com/karma-runner/karma-sauce-launcher/issues/73
which is not made clear in the original documentation.
In order to run the Karma tests, the Sauce Labs username
and access keys need to be passed in via the SAUCE_USERNAME
and SAUCE_ACCESS_KEYS env vars.
* Add a Karma configuration for unit/integration tests
for the client-side pywb code.
* Add an integration test suite which creates an <iframe> loads
the client-side rewriting code (wombat.js) in it and
then executes a test script.
Since wombat.js monkey-patches the DOM and the exact behavior
of DOM objects varies between browsers, which we want to test,
the suite does not mock the DOM but instead runs
a set of tests in an isolated environment against
the DOM.
* Add Travis config to run the Karma tests
