Removed composer.lock from repo since this is a 'library' and not the en...

I removed the `composer.lock` file due to issues I was having when running `composer install`.  Not all dependencies were in the lock file, meaning it was probably an old file that hasn't been updated.  After further research on [the Composer website](http://getcomposer.org/doc/02-libraries.md#lock-file), it seems since this is a "library," we should not commit the `composer.lock` file.  Instead, the end user should commit it in the repo for their application.