Add API to reset Fluent session to reuse docker container across multiple tests.

[mkundu1]

Currently we don't have an exposed way to reset the Fluent session. We need to look into having an API to do the same.

Originally posted by @mkundu1 in #222 (comment)

[mkundu1]

Not relevant, as launching a new container for each session is a cleaner approach and a standard practice in general.