v0.2.0

• Feature / BC break: Update to Stream v0.6 API and forward compatibility with Stream v1.0
  (#13 and #15 by @clue)

• Fix: Remove event listeners once closed
  (#14 by @clue)

• Improve documentation
  (#15 and #16 by @clue)

• Improve test suite by adding PHPUnit to require-dev and
  Lock Travis distro so new future defaults will not break the build
  (#11 and #12 by @clue)