Improve automation
Allow rspec args to be passed in to rake task
Wait for standalone worker shutdown in specs

Relates to #69
Colorize specs
Clean up the specs a bit
Validate authentication token before starting - Fixes #80
Merge pull request #80 from tildeio/validate-token

The agent should validate the authentication token on boot
Better config error messages and specs - #113
Small improvements to Builder config errors - #113
Remove unused (and broken) code
Run specs w/o RUBY_SKYLIGHT_NATIVE_PATH set
Improve error message for missing Skylight ext

Resolves #108
Don't assert started_at is a fixnum

This resolves tildeio/direwolf-agent#102
CHECK_NUMERIC should do what it says on the tin