test cases are executed twice

[mauriciovasquezbernal]

After #128 the test cases are executed twice, once when pytest --cov is run for the coverage targets and another one for the test targets itself.

See https://github.com/open-telemetry/opentelemetry-python/pull/128/files#r338632639.

[phalecs]

Hi @mauriciovasquezbernal can this be assigned to me?

[lzchen]

Also just to add, the tests are literally being run twice in tox.
https://github.com/open-telemetry/opentelemetry-python/blob/master/tox.ini#L5-L8

[Oberon00]

If we don't care about testing setup.py files, we could simply run all tests in a single environment. We could also configure travis to run a "quick check" first, i.e. lint + test everything in the same environment with only a single Python version and then only if that succeeded test+coverage for each package with multiple python versions separately.

[codeboten]

Closing this issue for now, it's not ideal but it's not getting in our way.