updating dependencies, addressing compiler warnings

[jeffgrunewald]

This PR is intended to update dependencies and address compiler warnings raised in newer versions of Elixir (1.11+)

With the shift to Elixir 1.11 and OTP 23 and above, dependencies expressly called on in an application that are not either a) included in the :extra_applications config of an app or b) listed in the app's dependencies will throw a compiler warning about implicit runtime dependencies. Since the :crypto module is built into Erlang, this should be added to the extra applications configuration to address this issue going forward.

I've also modified the version key based on the small size of the proposed change and my own take on semver but feel free to suggest a different version number change that you prefer.

Thanks so much!

[Hentioe]

This modification is meaningful and can eliminate some compilation warnings. @zyro

[Hentioe]

Unfortunately, the author does not seem to maintain this library anymore. Hope this library can be donated to others for maintenance 😃