v4.0.0 (2017-12-07)

• Updated to use NGSIv2 (NGSIv1 support dropped)
• Use case sensitive FIWARE-Service and FIWARE-ServicePath values to fix
  some problems
• Improved documentation
• Only create a subscription if the user configures attributes to monitor
• Connect to the context broker only after connecting the output endpoint
• Abort initial queries if the user changes operator preferences before
  retrieving initial values using previous configuration
• Initial test set using Karma and Travis CI