pip 10 build failure

[FRidh]

This package (3.2.1 and master) fails to build with pip 10.0.0:

File "setup.py", line 12, in <module>
    if 'docker-py' in [x.project_name for x in pip.get_installed_distributions()]:
AttributeError: 'module' object has no attribute 'get_installed_distributions'

The function get_installed_distributions is now part of pip._internal.

[FRidh]

Note this in effect breaks moto and thereby the testing of pandas.

[TomasTomecek]

I wonder whether function get_installed_distributions() was ever an official public API of pip.

[FRidh]

No, it was not.

pypa/pip#5154 (comment)

Although by not prefixing it with an underscore it never was that obvious. Until now then.

[FRidh]

Probably pkg_resources.working_set is best used here.

[adamtheturtle]

1d6f8ec#diff-2eeaed663bd0d25b7e608891384b7298 fixes this issue but is not yet released.

[FRidh]

Though not mentioned in PR or commit, a fix was merged as part of #1990.

@shin- can we get a 3.2.2?