User tag selector blacklist

[sidkshatriya]

See #96

[sidkshatriya]

This PR add the following features:

• Adds ability for phpunit tests to load options from a .options.json file
• Adds ability for amp-console to load options using the (new) --options=filename command line option
• Adds ability to pass certain CSS selectors as "blacklist selectors". If a blacklist selector is found, the tag is removed

[sidkshatriya]

I think we can merge this to master - If there are any tweaks required we can always include them later.

@marretjeca this is now available in the master branch of the library and you no longer need to switch to a specific branch of the amp-library.