build: establish current version in package.json

Ahead of moving to common merge tooling, the current version
of the packages must be tracked in the package.json at the root
of the project.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@angular/devkit-repo",
-  "version": "0.0.0",
+  "version": "10.2.0",
   "private": true,
   "description": "Software Development Kit for Angular",
   "bin": {