Enable the possibility of deploying multiple drivers when running TD distributed on K8s

[meirosucristina]

Description

Enabled to possibility of deploying more than one driver in order to
avoid having a single point of failure in the cluster. The drivers can
have one of the following roles:

• Master: is responsible for coordinating the entire execution in the cluster (sends Heartbeat messages to periodically check that the agents are still up and running, divides the phases from the initial configuration into multiple tasks to be distributed between the agents, etc).

• Candidate: it can replace the current Master in case of failure.Candidates are responsible for periodically sending Heartbeat messages to the current Master to check that it is still running properly.

Related Issue

See issue #13

Motivation and Context

How Has This Been Tested?

Manually & JUnit tests.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.