XDCR changes for collections breaks build sanity and simple test

Latest change for collections for XDCR breaks sanity and simple test

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21:47:58 ERROR: uniXDCR (unittest.loader._FailedTest)
21:47:58 ----------------------------------------------------------------------
21:47:58 ImportError: Failed to import test module: uniXDCR
21:47:58 Traceback (most recent call last):
21:47:58 File "/usr/local/lib/python3.7/unittest/loader.py", line 154, in loadTestsFromName
21:47:58 module = _import_(module_name)
21:47:58 File "pytests/xdcr/uniXDCR.py", line 8, in <module>
21:47:58 from .xdcrnewbasetests import XDCRNewBaseTest
21:47:58 File "pytests/xdcr/xdcrnewbasetests.py", line 30, in <module>
21:47:58 from collection.collections_rest_client import Collections_Rest
21:47:58 ImportError: cannot import name 'Collections_Rest' from 'collection.collections_rest_client' (lib/collection/collections_rest_client.py)
21:47:58