General meta cleanups.

Nothing to see here.
some general lib cleanups

No behaviro changes, mostly style cleanups.
test suite and setup cleanups

Mostly cleanups to the style and some main helper changes.  Biggest
change is I have the main helper add the root dir to the load path
so I can run the tests from any directory, not just the root dir.
updates pid file tests to not assume running out of the root dir

These tests were breaking if you didn't run them from the root dir.
fail nicely if trying to write the pid file to a dir that is not writeable

Before this would error with a cryptic `Errno::ENOENT` error that went
something like "No such file or directory - /path/to/pid/file.pid".

This changes it to raise a `RuntimeError` that says "PID file dir
`/path/to/pid` is not writeable".

The whole point of this is to help the user out and to better direct
them to fix the problem.

Closes #63.
pluralize test contexts and file names

Just updating the test suite to our conventions.
Merge pull request #70 from redding/kr-cleanups

A bunch of cleanups