Improve the README so it lines up with the Packer docks

If you're coming from Packer it should be easier to use this library. This keeps the names of provisioners, builders, post-processors in line with what you'd find the Packer.io documentation so it's easy to reference them.
Merge branch 'master' into develop

* master:
  Fix missed merge conflicts and broken tests
  Prep for 0.0.4 release
  Switch to the new Packer::Runner for executing commands
  New Runner class
  Bump version to 0.0.3
  Add UTF-8 encoding line for Ruby 1.9.3
  Make pretty print optional, handle paths on output files, implement delete
  Pretty print the JSON output
  Update example so it is a working example
  Add a :clean task and exclude JSON files created by integration tests
  First pass at some integration testing
  Disable travis-ci auto-push to RubyGems
Fix broken tests

Rubocop and some spec tests were broken with the latest versions of the
dependent libraries.
Drop support for Ruby 1.9

Sorry, too not worth it. 2.x and up.
Merge branch 'release/v0.0.4'

* release/v0.0.4:
  Drop support for Ruby 1.9
  Introduced streaming output support for #build
  Fix broken tests
  Improve the README so it lines up with the Packer docks
  Actually wrote a RELEASENOTES file