PR: Address pylint's "consider-using-with" warnings

[krassowski]

Fixes #19 by adding context managers in all places flagged by consider-using-with. ExitStack was added in places where the simple with statement cannot be used.

[ccordoba12]

ExitStack was added in places where the simple with statement cannot be used.

I disagree with this change because it makes the code too cumbersome for no good reason. Please skip those Pylint warnigns instead.

[krassowski]

Ok, I reverted the ExitStack use as I have no strong opinion here. I agree that the case for having the context manager is not strong here - it may help in some extreme circumstances, but communicate() should normally terminate the process and not terminating the process should not have terrible consequences anyway.

[ccordoba12]

it may help in some extreme circumstances, but communicate() should normally terminate the process and not terminating the process should not have terrible consequences anyway

Agreed.

[ccordoba12]

Thanks @krassowski!