v1.0.0: Semantically Versioned

Pattern Lab is now using semantic versioning for release versioning. This is being done for two reasons. The first is an acknowledgment that Pattern Lab is being used by a number of people in production environments. The second reason is that the next release will break backwards compatibility and we want to be able to clearly convey that. There are no real differences between v0.7.12 of Pattern Lab and v1.0.0.