aptible login, aptible version, aptible config(:rm|:add)

Closes #1
Closes #3
Fix error messages on bad tokens

Also, fix saving multiple tokens to ~/.aptible/tokens

Fixes #4
The Rubocop strikes again
Disregard JRuby for now
Merge pull request #5 from fancyremarker/config-add-rm

Initial functionality
aptible ssh (closes #6)
Bump version
Fix default command parsing (fixes #14)
Properly use default app handle (fixes #13)
Merge pull request #15 from fancyremarker/v0.3.1-fixes

Two fixes for v0.3.1
Bump aptible-api dependency and remove aptible-auth (see #7)
Slight require optimization
Merge pull request #16 from fancyremarker/pin-dependencies

Pin dependencies
Add :email/:password options to login (fixes #17)
Appease Rubocop
Bump version
Merge pull request #18 from fancyremarker/login-options

Add :email and :password options to `aptible login`