Make tests work again

[robinedman]

• It's now possible to run the tests again (was broken due to changed path to Immutable and previously by lodash upgrade).
• This unveiled a failing Firefox test. See commit comment for details.
• scribe-common and .lodash are no longer used. Removed them as bower dependencies.
• Updated the Travis browser matrix since we were testing on outdated browsers

Tests still won't work by default in Firefox since the selenium version is outdated. Opened https://github.com/guardian/scribe-plugin-noting/issues/139 Update: sorted!

[hmgibson23]

:+1:

[robinedman]

All green now: https://travis-ci.org/guardian/scribe-plugin-noting/builds/69457314