Added doctest for the README.md ensuring client examples are correct.

Also - note that the code block of the markdown file (denoted by ending & closing \`\`\`) needs to have a blankline following the doctest blocks of the last test file fail.  I'm not sure what the quirk here is.  I think the answer most would give might be "use reStructured Test instead".
Merge pull request #8 from kissmetrics/ajl/add-doctest-readme

Added doctest for the README.md ensuring client examples are correct.
update setup.py to automatically generate requires
wrong keyword
Merge pull request #10 from kissmetrics/requirements

update setup.py to automatically generate requires
also fix install_requires
Refactor the QueryString class into a function

Since it was a one-method class.
Removed the "_string" name from the function - you could identify that it's a string if you needed to know that.
Refactor away some of the mutable default argument handling.
Refactor some of the url and request duplication in client.py
remove url attribute from Client
use dict.update rather than an unnecessary loop
Merge pull request #12 from kissmetrics/brian_curtin

refactors thanks to @briancurtin and @njm
Merge branch 'master' into ajl/docstr-issue-5
Corrected one-line summary.
Corrections for tense.