Update pip to at least 9.x

[acdha]

The current base image for Python has pip 6, which is ~2 years old. I noticed this when my builds broke today after the requests team shipped an update which depends on a pip feature which is roughly a year old:

https://github.com/kennethreitz/requests/issues/4006

Adding pip install --upgrade pip to the install stanza of my .travis.yml fixes it but that has to be done for every project.

[BanzaiMan]

Recent Python archives may have a version of pip that satisfies your needs. For example, 3.5 has pip 9.0.1 on Precise, 8.1.2 on Trusty.

[cotsog]

FYI, requests 2.14.1 was shipped and it

should vastly widen the number of supported pip and setuptools versions

(from: https://github.com/kennethreitz/requests/issues/4006#issuecomment-300269007)

Can anybody confirm if it's fixed on Travis CI without the pip install --upgrade pip workaround?

Thanks!

[stale]

Thanks for contributing to this issue. As it has been 90 days since the last activity, we are automatically closing the issue. This is often because the request was already solved in some way and it just wasn't updated or it's no longer applicable. If that's not the case, please do feel free to either reopen this issue or open a new one. We'll gladly take a look again! You can read more here: https://blog.travis-ci.com/2018-03-09-closing-old-issues