v2.0.1

Added

• examples/auth_check.rb, a standalone script that shows which
  credentials SP-API accepts. It calls the Orders API with a made-up
  token and with a real access token, then asks LWA for a refresh with
  and without the app credentials, and prints what each answer means.
  It depends on nothing but this gem, or on Net::HTTP when the gem is
  not in the bundle. examples/ is not part of the built gem.
• rake release:prepare[X.Y.Z] prepares a release on a laptop: it
  runs the suite, sets the version, dates the CHANGELOG entry, relocks
  the lockfiles, commits and tags. Pushing the tag still publishes.

Changed

• The README and the spec comments no longer name any particular
  consumer of the gem. lib/ and vendor/ are unchanged; for a
  consumer, 2.0.1 is 2.0.0 with a new README.