setup.py install installs tests

[christophgysin]

I'm packaging awslogs for archlinux on https://aur.archlinux.org/packages/awslogs

When installing awslogs with:

python setup.py install

It also installs the tests under the generic name tests. This conflicts with other packages that have the same issue.

I suggest to exclude the tests from being installed.

[christophgysin]

This is a duplicate of #322