Implement Poller that retries endpoints when encountering some pre-specified Atlas API errors

[prashantmital]

In several places we are doing something like:

timer.start()

while True:
    try:
        # do stuff
    except AtlasApiError as exc:
        if exc.error_code not in [List of error codes to retry on]:
            raise
        sleep(...)
        continue
    else:
        # we did what we needed to do, exit
        break
    finally:
        if timer.elapsed > MAX_WAIT:
            raise Exception('unable to do stuff')

We should create a concrete subclass of PollerBase

drivers-atlas-testing/astrolabe/poller.py

Line 27 in 5bf2456

class PollerBase:

that is tailormade for this purpose.