feat(auth): Adds support for importUsers API. (#220)

* feat(auth): Adds support for importUsers API.
This API can be used for bulk account import to Firebase Auth user database
from external Auth systems using different hashing algorithms as well as
other Firebase projects.

fix(auth): Fixes quota exceeded errors thrown in auth integration tests due
to backend throttling.

* Fixed linter errors.

* Addresses review comments.

* Additional fixes added.

* Improved comment.

* More comment tweaks.

* Addressed more comments.

* More fixes.

* More fixes.

* Addressed review comments.

* More review comments addressed.

* Adds email to provider in Auth integration importUsers test for multiple
OAuth providers. This helps test provider emails are correctly set.

* Adds customClaims integration test to importUsers test.

* Updates package-lock.json.

Author: bojeil-google

package-lock.json

@@ -63,13 +63,14 @@
     "@types/chai": "^3.4.34",
     "@types/chai-as-promised": "0.0.29",
     "@types/firebase-token-generator": "^2.0.28",
-    "@types/lodash": "^4.14.85",
-    "@types/mocha": "^2.2.32",
+    "@types/lodash": "^4.14.104",
+    "@types/mocha": "^2.2.48",
     "@types/nock": "^9.1.0",
     "@types/request": "2.0.6",
-    "@types/request-promise": "^4.1.33",
-    "@types/sinon": "^4.1.2",
+    "@types/request-promise": "^4.1.41",
+    "@types/sinon": "^4.1.3",
     "@types/sinon-chai": "^2.7.27",
+    "bcrypt": "^1.0.3",
     "chai": "^3.5.0",
     "chai-as-promised": "^6.0.0",
     "chalk": "^1.1.3",
@@ -79,25 +80,26 @@
     "gulp": "^3.9.1",
     "gulp-exit": "0.0.2",
     "gulp-header": "^1.8.8",
-    "gulp-istanbul": "^1.1.1",
+    "gulp-istanbul": "^1.1.3",
     "gulp-mocha": "^3.0.1",
     "gulp-replace": "^0.5.4",
     "gulp-tslint": "^6.0.2",
-    "gulp-typescript": "^3.1.2",
-    "lodash": "^4.6.1",
-    "merge2": "^1.0.2",
+    "gulp-typescript": "^3.2.4",
+    "lodash": "^4.17.5",
+    "merge2": "^1.2.1",
     "minimist": "^1.2.0",
     "mocha": "^3.5.0",
-    "nock": "^9.1.0",
+    "nock": "^9.1.8",
     "npm-run-all": "^4.1.2",
-    "nyc": "^11.3.0",
+    "nyc": "^11.5.0",
     "request": "^2.75.0",
     "request-promise": "^4.1.1",
     "run-sequence": "^1.1.5",
-    "sinon": "^4.1.3",
+    "scrypt": "^6.0.3",
+    "sinon": "^4.3.0",
     "sinon-chai": "^2.8.0",
     "ts-node": "^3.3.0",
     "tslint": "^5.9.0",
-    "typescript": "^2.6.1"
+    "typescript": "^2.7.2"
   }
 }