Added travis configuration and script to automatically deploy new docs when there are any changes to master

Completed Error Handling Cleanup

Implemented From trait for the ReadlineError enum in order to faciliate mapping from io::Error or nix::Error to ReadLineError

Added a new module that will contain constants

Added documentation, fixes #4

Completed implementation of ReadlineError

* You can now read 1 character at a time in raw mode

Readline will now return Result<> instead of Option<>.  Additionally, added readline_raw function to handle raw mode reads from stdin

Removing Cargo.lock from the repo