Add favicon.ico

[mbramson]

Adds a favicon.ico to the assets of the file.

TODO:

• Add reference from the Endpoint file
• Copy this over to priv/static via Webpack
• One of:
  • Get Add copied_files option which specifies binary files to copy pragdave/mix_templates#9 merged
  • Call out using the forked branch archives instead of master mix_templates and mix_generator in the README when using the webpack option so that people don't see errors.

Blocked by pragdave/mix_templates#9