Exclude pip 9.0.2 specifically from test-requirements

[virresh]

Due to a recent pip update to 9.0.3 that reverts the changes brought in pip 9.0.2, we should ideally just bar pip 9.0.2 and allow other versions here

Relevant links :
#2359
pypa/pip#5081 (comment)

[jayvdb]

And also prevent use of pip 10.0, but allow pip 10.1 , basically preparing for 10.0 being quite disruptive, but the problems will sort themselves out by 10.1

[aadilmehdis]

Hi, I'd like to work on this issue as a newcomer, can you help me get started?
@virresh

[virresh]

Hello @aadilmehdis
You need to modify this line appropriately for the purpose of this issue.

If you would like an insight into what the actual problem is, consider reading the related links in the description

Also probably requirements specifiers might be useful for this issue

Head over to the gitter channel if you feel stuck

[aadilmehdis]

What versions of pip are to be excluded @virresh.
From the comments, I understand that the version 9.0.2 and 10.0 are to be specifically excluded.

[virresh]

@aadilmehdis
Yes, we need to specifically exclude version 9.0.2 and 10.0

[aadilmehdis]

@virresh
Hey, so making this change in the line would be okay?
pip<=9.0.3 , != 9.0.2, != 10.0.*

[virresh]

Why would you use <= 9.0.3 ?
I think the two latter specifiers should suffice.

[aadilmehdis]

Okay. Now to push in the changes, I just commit the changes and push my development branch and create a pull request right?