Add test for remote worker path resolution

[furtib]

Why:
We want to test our solutions for making remote workers' absolute paths into locally usable relative paths. We should add a test for it.

What:
Adds a new test to run on pre-created remote worker paths.

Addresses:
#65

[Szelethus]

I'm fine with creating/removing the tmp directory with a class level setup/teardown, but by having a global PATH_RESOLUTION, you practically do 90% of the test in those methods. In fact, I'm not even sure the way you are testing there is a need for creating any files. I recommend that you simply test the string replace, which is all that really matters here.

[Szelethus]

This is a very intrusive test. You are not testing the entirety of this function, only this part:

data = data_file.read()
for pattern, replace in BAZEL_PATHS.items():
    data = re.sub(pattern, replace, data)

Lets just create a separate function that takes some string and returns with a substituted one. One something like that. That way you won't need to add an intrusive parameter just for testing.

[furtib]

We could just import the list of regexes from here, to not be so intrusive.

[Szelethus]

Awesome, this is what I wanted to see! I have some nits, but otherwise this is a great PR.

[Szelethus]

Why do we need this global variable? We could just pass each of these as an argument.

[furtib]

I thought it would be easier to test other methods we might add in the future, this way.