remove mix.lock file

lockfiles are for applications, not libraries
update to elixir v0.11.x
update elixir version in .travis.yml
Merge pull request #1 from reset/ex-11

Update to Elixir 0.11.x
Add _build to .gitignore

[ci skip]
bump to elixir 12
update travis.yml for ex12
Merge pull request #3 from reset/elixir-12

bump to elixir 12
Update to hackney 0.10.0 (thanks to @benoitc)

hackney 0.10.0 can now send async response to a specific process

https://github.com/benoitc/hackney/commit/2731c0d6fc101f3ea801a3821dad9194ff29679d
Add async request to HTTPoison
Update README.md
Merge pull request #4 from edgurgel/async-request

Async request
Update README.md

[ci skip]
Use a simple recieve instead of CaptureIO

Also make tests async.
Allow ssl application to be started recursively
Merge pull request #5 from devinus/master

Improvements
Update Hackney to 0.10.1

Also fix deprecation warnings on Elixir 0.12.1.
Merge pull request #6 from devinus/master

Update Hackney to 0.10.1
Bump version 0.0.2
Replace <- with send for elixir v0.12.2