Release v0.1

Main changes:

• AGENT_ENV_FILE variable for the path to the Agent environment variables
• ResponseSelector can run as a service
• multi-stage annotators
• empty annotators allowed
• save Mongo DB data even if the mongo container is killed
• DeepPavlov 0.6.0 compatibility

Useful utils:

• a script for Mongo DB data dump
• monitoring of current state (static) in a browser window
• a script for testing Agent HTTP API from ready dialogs
• a script for generating dialogs from phrases
• a script for testing the Agent in a batch mode