Use newest Elixir version

Fix deprecated warnings

Process Commands raises on unexpected input (Stopgap for #14) (#15)

run server using unix domain socket (#16)

Update travis config

Fix a bunch of test issues

Parsing --port argument as integer (#13)

No need to uniq the completion candidates

Update Elixir version test environment

Merge pull request #9 from slashmili/socket-server

Implement communication with server via socket

Merge pull request #7 from slashmili/cmd-ping

Added test for PING command

Added PING command

Separate failing code from regular code (thx @lexmag)