set up library so it can run a suite standalone in python

[jeanetteclark]

similar to what the R package does, this should include methods for

• runCheck
• runSuite

runCheck might instead be implemented as a decorator such that a user could write a check that looks like:

@check
def myCheck(param1, param2):
    ...
    return(result)

the decorator could:

• prepare selectors (eg: get data files and parse them)
• collect output into the correct format
• handle some error and edge case checking

Advantages are that people writing checks need to think less about the items above, disadvantages are that it obscures all of that, and leads to the possibility that users can run a bunch of checks simultaneously which we don't want

[jeanetteclark]

re-classifying and prioritizing this issue since it will be much easier to test new data quality checks when this is done