Rework errors and backoff logic

• New error structure and new error types
• Backoff logic retries API calls on non-cirrus errors and exceptions, even if they're not HttpErrors

more error handling and logging

more error handling and logging for add-member to group

bug fix for error handling

don't re-raise exception if we handle it

add retry for google requests

Merge pull request #42 from uc-cdis/fix/backoff

fix(backoff): backoff to retry google API calls

SA Delete 400 Error Fix

Handles 400 Error from Google API when deleting SA gracefully.

Adds Open/Close Functions for Manager

Adds Open/Close Functions for Google Cloud Manager objects. Allows GCMs to be opened/closed multiple times while only calling initialize code once and clean up code once.

Fix bug with nonexistent service account

0.1.7

fix(sa-type): handle nonexistent service account (return false for va…

Fix service account type handling

fix(sa-type): correct domains for checking service account types (#37)

* fix(sa-type): correct domains for checking service account types

* fix(tests): update SA type tests

* chore(tests): update test for new sa types

use_default arg to disallow defaulting google project

0.1.5

feat(default-project): arg to dissallow defaulting to configured proj…

fix get parent org function

0.1.4

fix(get-parent-org): raise exception if there's an error during googl…