Small typo in the doc

But it could be confusing for some ;)
Merge pull request #8 from lra/typo

Small typo in the doc
add a test to demonstrate waiting for a missing key
flake8; assert the first get is empty
timing tweaks to make the tests more robust
assert kv.put/get work with binary strings
timing tweaks to make the tests more robust
update TODO
assert the value for kv.put is a string
assert value for kv.put is either None or a string; update documentation
timing tweaks to make the tests more robust
typo
addition of check api to register, deregister and inspect node and service level checks.
Made formatting and other suggested changes to check api
fix pep8 line length errors.
Merge pull request #12 from sgargan/check_api

Addition of Checks API to agent
tweak timings to make the tests more robust
tweak timings to make the tests more robust
add TODO for wan flag
tweak timings to make tests more robust