- added test cases from the official Akamai-OPEN GitHub
  repository
- Thanks to Jonathan Landis from Akamai for providing
  hints and advices for the code/API and the test cases
  for the test suite
- their implementation can be found at the official
  Akamai-OPEN GitHub page:
  https://github.com/akamai-open/AkamaiOPEN-edgegrid-perl
- added header signing functionality which is needed for
  future Akamai APIs
- added Changes file to dist
- updated version tags to 0.02