Missing colons before datatypes in variable names in docs

[yotam-stsci]

Very minor issue: All the variable names in the docs for the primary user interface (https://drizzlepac.readthedocs.io/en/latest/astrodrizzle.html) are missing a colon and some spaces between the variable name and datatype (e.g. "outputstr should be output : str"). This issue was not present in the deployment version.

[mcara]

It may be a minor issue but very annoying. It looks like this is caused by using sphinx version 2.0.0 and higher. I will specify in the requirements to use sphinx<=1.8.5 using which the documentation seems to be rendered correctly.

[mcara]

Solved via #378