Fix coveralls/boto3 dependency conflict (#93)
Fix coveralls/boto3 dependency conflict (#93)

Both coveralls and boto3 require urllib3.
But for Python 2.7 coveralls requires urllib3[secure]<1.25,>=1.21.1
when boto3 requires botocore which requires urllib3>=1.20,<1.26.

Pip installs version that's required first
because it has no dependency resolver.
See https://github.com/pypa/pip/issues/988 for details.

So we have to move coveralls upper to fix the issue.

Fixes #91

These changes also:

 - Unpin pytest
uber-common/opentracing-python-instrumentation,uber-common/opentracing-python-instrumentation