Fix the Simulation Manager to fail properly in case of GAMA failure.

[chintanp]

• Changed Bee to Bull. :heavy_check_mark:
• Can better handle failures and errors now.
• Need to make it better at logging, and report failures on redis connection, DB connections etc.

[chintanp]

• Check tripgen calculations :heavy_check_mark:
• Work on instance termination, on a second trigger when trips are generated. :heavy_check_mark:
• Create CW dashboard for the incoming logs.
• Test with various charging scenarios.

[chintanp]

• Use EC2 role with worker instances instead of API keys. :heavy_check_mark: