[Environment] Remove dependency on ruby 2.

Because it's actually unnecessary, and it makes running in travis
more complicated.
[Environment] Add gems we'll need

mail to send emails (uploads to strava.com)
and test-unit because we'll write tests.
[Environment] A rakefile that does something

Run some tests in the rakefile
[Upload] Adds a very basic upload interface.

The various uploaders will implement it.
[Testing] A very simple test email server.

That we can use for tests.
It listens on port 2525
[Upload] Adds an uploader for strava.com

It just sends an email with the file attached to strava.com