Explictly sets the prefix when building node
Show full backtrace on exceptions

From conversation https://github.com/grosser/parallel_tests/issues/221
roll up warnings at the end so they don't get lost
don't print warnings if there aren't any
Detect rails 4 manifest file
Add Hatchet test and Rails 4 manifest repo to sharpstone (
https://github.com/sharpstone/rails4-manifest )
un-focus rails 4 spec
Fix rubies spec

Version numbers have been revved, removing patch number from test.
Parallel tests

Run rspec tests in different processes for different files. Speeds up testing by roughly 6x.
match all ruby 1.8.7 for setting up bundler/syck
Check if ruby_version is not nil before running .match against 1.8.7
bump v62
update changelog
Setting up travis testing
Bump Hatchet Dependency

- Hatchet now raises an error on failure, must flag `allow_failure: true` if you expect a failure on builds.
- Hatchet no longer masks `Anvil::Builder::BuildError` exceptions
- Hatchet::App#push! for both Git and Anvil now returns just an output string. On failures an exception will be raised
Hatchet knows how to set itself up on Travis CI

Run `bundle exec rake hatchet:setup_travis` instead of manually running each command
Auto Retry deploy failures 3 times on travis

When a deploy fails hatchet will now retry a deploy HATCHET_RETRIES times before raising an error. This mitigates ghosts in the machine and makes the test suite's red/green status more truthy.
extract cache into its own class
document when cache_dir is nil
extract metadata into its own class
store buildpack ruby_version data