2.3.0

• Better handling of Content-Types. When following HAL links that have a
  type parameter, the type is rememebered and used in Accept and
  Content-Type headers, for GET, PUT and POST requests.
• If no type was provided, it will use the last Content-Type header from
  GET response.
• If that GET request never happened, it uses the first 'default'
  Content-Type from client.contentTypes, and enumerates all mime-types from
  that list for Accept headers.
• No longer incorrectly sends text/plain Content-Types.
• Optimization: If multiple calls are made to ask for a Resource's current
  representation, all these calls are coalesced into one. The big benefit is
  that there are no longer multiple parallel GET requests.
• Webpack browser build is set to 'production' mode.
• Fixed: After refreshing an OAuth2 token, the new access token wasn't used.