Added parameter driver: string to supported(), see https://github.com/tymondesigns/angular-locker/blob/master/src/angular-locker.js#L143:53 for the definition in the original source.

• [ ✔ ] Use a meaningful title for the pull request. Include the name of the package modified.
• [ ✔ ] Test the change in your own code. (Compile and run.)
• [ ✔ ] Follow the advice from the readme.
• [ ✔ ] Avoid common mistakes.
• [ ✔ ] Run npm run lint package-name (or tsc if no tslint.json is present).

If changing an existing definition:

• [ ✔ ] Provide a URL to documentation or source code which provides context for the suggested changes: https://github.com/tymondesigns/angular-locker/blob/master/src/angular-locker.js#L143:53
• [ nope ] Increase the version number in the header if appropriate.
• [ nope ] If you are making substantial changes, consider adding a tslint.json containing { "extends": "dtslint/dt.json" }.