Remove node_modules from the repo

* Removed the `node_modules` directory from the repo
* Updated version of `should` to use semver compatible version of `should`
  - This is necessary because the version installed from npm now does not work with the tests, since the tests use `should.includeEql` which appears to have been removed in the latest version
* Updated .npmignore
   - Since `node_modules` is no longer in the repo, does not need to be in .npmignore
   - The `test` directory is not necessary for people npm installing the repo
   - There is no file/directory named `coverage` in the repo, thus is does not need to be ignored