PEP 257 testing
Actually installing the pep257 tool helps
Proper invocation of pep257
Ignore laterpay.django for docstring testing
Ignore PEP 247 D203 (blank line before docstring)
Don't require single-line docstrings to be on one line
Some docstring fixes

These are far from fabulous, but they're a start at least.
Optimistically disable allowed failures for PEP 257 checks
s/private/internal/ - underscore prefix, not name mangling
Clarified deprecation plans around APIException
Merge pull request #28 from laterpay/feature/docstrings

PEP 257 testing