chore(package.json): update dist-tag for 1.7.x

Author: petebacondarwin

package.json

@@ -3,7 +3,7 @@
   "license": "MIT",
   "branchVersion": "^1.7.0",
   "branchPattern": "1.7.*",
-  "distTag": "latest",
+  "distTag": "previous_1_7",
   "repository": {
     "type": "git",
     "url": "https://github.com/angular/angular.js.git"