construct urls with standard library tools

addresses #14
positional arguments are so meh
reimplement _request method to wrap urlparse
Merge pull request #15 from kissmetrics/urlparse

Build URLs using the standard library
Added periods for first lines of docstrings.
Made final docstring lines consistency with PEP257 recommendation.
Made final docstring lines consistency with PEP257 recommendation.
Removed extra new line.
Merge pull request #11 from kissmetrics/ajl/docstr-issue-5

Provided docstrings for ``client.py``