fix: change the environment ID key for CLI

Description

Fix the invalid environment ID flag

[root@vm-stag-postgresai-joe-0 ~]# dblab init --environment-id=tutorial --url=http://1.1.1.144:3000 --token=secret_token --insecure
2020/03/03 04:40:03 environment_id must not be empty

Checklist

• the MR description has been reviewed
• this MR contains text changes and they have been reviewed OR there are no texts changes
• this MR contains GUI/CLI changes and they have been reviewed OR there are no GUI/CLI changes
• this MR contains API changes, specifications reflect those changes and they have been reviewed OR there are no API changes