add check to ensure that any new file has the license in the header

**What do you want to happen?**

I am as maintainer would like to automatically ensure that any new file added to the project has a license. 

**Possible Solution**
Use the same check that we have in the SDK https://github.com/operator-framework/operator-sdk/blob/master/hack/check-license.sh. 

/kind feature
