Adds two trivial tests, initial Travis CI config, minor nits

Adds two new test files (glide_test.go and cmd/get_imports_test.go) to provide at least one test to run in each package.

Adds a Travis CI config file.  I'll need a maintainer to enable Travis builds for the main repo.  Here's the passing build for this branch/PR: https://travis-ci.org/lamielle/glide/builds/38120856

Fixes a few spelling/whitespace nits.