Correct "apt uninstall" -> "apt remove"

[jason-curtis]

Previously, apt uninstall would correct to apt install but this is more of the desired behavior

I considered putting this in a separate rule, apt_uninstall, with a higher priority than apt_invalid_operation but this seemed like a more straightforward approach. If there's a preference for doing it that way I can do that instead.

[ik1ne]

Running flake8 (PROJECT_DIR)/thefuck/rules gives following error:

thefuck/rules/apt_invalid_operation.py:4:1: F401 'thefuck.utils.replace_argument' imported but unused

I think removing that import will make PR pass the CI build.

[jason-curtis]

oops, didn't see that this had failed. fixed!

[nvbn]

Looks good, thanks!

[nevercast]

Just the feature I was looking for, time to update my local thefuck copy! Thanks @thatneat