v4.1.3: Update codebase for obt7 (#112)

* use chai should explicitly

* use if statements to improve readability

* use forEach instead of filter as we are not using the returned array for anything at all

* remove unneeded semicolon

* move instance method to static method as it does not use any instance properties or methods.

* fix indentation

* Wrap cases in blocks to stop lexical declarations being hoisted to start of switch statement

* Add a default case to capture scenarios where and ad has a type we not match against

* Fix linting issues in sass

* use proclaim instead of chai as to conform with all other origami components

* Remove features not needed for obt7

* fix linting issues

* Update circle.yml

* Update ads.js

* Update ads.js