…s environments.

Adding MongoDB to index
Adding MongoDB to README
Adding bulkWrite detection, refactoring method of deriving trace key
Refactoring MongoDB tests with connection convenience method (uses MongoDB-preferred connection params)
Refactoring post-linting
Additional way of detecting host and port for insert/find/update/delete methods.
Replacing copy-paste duplication
Refactor of host/port extraction, support for separate delivery of bulk commands in request.data, expanding traced cursor ops.
Refactoring timeline test, adding callback to bulkWrite test, delinting
Commented-code cleanup, commenting out tests that depend on MongoDB in the local environment, so that CircleCI passes.
Updating MongoDB auto-trace info in README
Explicitly awaiting plugin load in trace constructor
Capitalization change to dbType for compatibility with Python collector
Removing commented-out logs in test.