1.9.0

Released on June 2nd 2020

• Added an option to include the functions source code when generating the cache
  key. PR #156.
• Added a new feature that allows one to completely control the way how cache keys
  are generated. For example, one can now implement a function that generates
  cache the keys based on the POST-based requests.
  PR #159.
• Fixed a few cache backend naming collisions by renaming them from simple to
  simplecache, null to nullcache and filesystem to
  filesystemcache.
• Explicitly pass the default_timeout to RedisCache from
  RedisSentinelCache.
• Use os.replace instead of werkzeug's rename due to Windows raising an
  OSError if the dst file already exist.
• Documentation updates and fixes.