Simplified it and integrated it with git

Here are the changes that were made:

+ It bumps the version using [semver](https://npmjs.org/package/semver), the official package that was built to handle stuff with versioning (written by [isaacs](https://github.com/isaacs))
+ It can bump the build version (because now it's using semver)
+ When bumping the version, it makes a commit with `package.json` saying that the version was bumped
+ After commiting, it tags said commit
+ It's asynchronous (because it has to perform the git things)
+ Removed tests and testing suite. The only reason why tests were needed was for testing that the old system bumped versions correctly. Since this now uses semver, and semver is tested by the Node community, you don't have to test that it will increment versions correctly.

The original coding style was kept intact (I think).