Merge branch 'add_support_for_db_environment' into 'master'

beat/backend/python/database.py

...ckend/python/test/prefix/databases/integers_db_env/1.json

...backend/python/test/prefix/databases/integers_db_env/1.py

...ckend/python/test/prefix/databases/integers_db_env/2.json

...backend/python/test/prefix/databases/integers_db_env/2.py

beat/backend/python/test/test_database.py