Update dependencies to reduce vulnerabilities. (tensorflow#1592)

SECURITY

Author: Nikhil Thorat

package.json

@@ -23,11 +23,11 @@
     "clang-format": "~1.2.4",
     "jasmine": "~3.1.0",
     "jasmine-core": "~3.1.0",
-    "karma": "~2.0.2",
-    "karma-browserstack-launcher": "~1.3.0",
+    "karma": "~4.0.0",
+    "karma-browserstack-launcher": "~1.4.0",
     "karma-chrome-launcher": "~2.2.0",
     "karma-jasmine": "~1.1.0",
-    "karma-typescript": "~3.0.12",
+    "karma-typescript": "~4.0.0",
     "npm-run-all": "~4.1.3",
     "rimraf": "~2.6.2",
     "rollup": "~0.58.2",