Remove unneeded path to mocha binary.

npm will set up $PATH such that the binaries installed to node_modules will be available.
Move dependencies to development dependencies.

None of these are needed at runtime, no one should have to install them just to use this library.
Fix a typo that caused the tests to fail.
Merge pull request #3 from eventualbuddha/master

Remove unneeded dependencies & misc. fixes.