chore: add lockfile to git, and add build target to refresh the lockfile (#446)

Author: alharris-at

.gitignore

@@ -24,5 +24,4 @@ packages/*/package-lock.json
 packages/**/reports/junit/*
 test.out.log
 *.tsbuildinfo
-yarn.lock
-package-lock.json
+package-lock.json

package.json

@@ -30,7 +30,8 @@
     "rm-dev-link": "rm -f \"$(yarn global bin)/amplify-dev\"",
     "commit": "git-cz",
     "coverage": "codecov || exit 0",
-    "split-e2e-tests": "yarn ts-node ./scripts/split-e2e-tests.ts && git add .circleci/config.yml"
+    "split-e2e-tests": "yarn ts-node ./scripts/split-e2e-tests.ts && git add .circleci/config.yml",
+    "refresh-lockfile": "rimraf yarn.lock && yarn"
   },
   "bugs": {
     "url": "https://github.com/aws-amplify/amplify-codegen/issues"