Remove Guard

[tfausak]

I don't want to bother dealing with Guard after guard/listen#371.

[e2]

I don't want to bother dealing with Ruby < 2.2. Neither does the Ruby core team....

[tfausak]

I don't blame you. Dropping support for a version of Ruby is a breaking change. That is a change that should be made as part of a major version change.

[e2]

@tfausak - it wasn't about "dropping support". Support was already officially dropped - it was a bug that the dependency wasn't updated.

Also, according to SemVer, what I did was fine.

[e2]

Just FWIW: The current release candidate for Bundler resolves this: on 1.9.3 even, it correctly uses a version of Listen installable with Ruby 1.9.3.

All you'd need to do is put gem install bundler --pre in your Travis config.