chore(deps-dev): bump node-fetch from 1.7.3 to 2.6.1

Bumps [node-fetch](https://github.com/bitinn/node-fetch) from 1.7.3 to 2.6.1.
- [Release notes](https://github.com/bitinn/node-fetch/releases)
- [Changelog](https://github.com/node-fetch/node-fetch/blob/master/docs/CHANGELOG.md)
- [Commits](node-fetch/node-fetch@1.7.3...v2.6.1)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -46,7 +46,7 @@
     "firebase-token-generator": "^2.0.0",
     "lolex": "^2.3.1",
     "mocha": "2.3.3",
-    "node-fetch": "^1.7.3",
+    "node-fetch": "^2.6.1",
     "nyc": "^11.4.1",
     "rimraf": "^2.6.2",
     "source-map-support": "^0.5.0",

yarn.lock

@@ -1996,13 +1996,18 @@ neo-async@^2.6.0:
   resolved "https://registry.yarnpkg.com/neo-async/-/neo-async-2.6.2.tgz#b4aafb93e3aeb2d8174ca53cf163ab7d7308305f"
   integrity sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw==
 
-node-fetch@^1.0.1, node-fetch@^1.7.3:
+node-fetch@^1.0.1:
   version "1.7.3"
   resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-1.7.3.tgz#980f6f72d85211a5347c6b2bc18c5b84c3eb47ef"
   dependencies:
     encoding "^0.1.11"
     is-stream "^1.0.1"
 
+node-fetch@^2.6.1:
+  version "2.6.1"
+  resolved "https://registry.yarnpkg.com/node-fetch/-/node-fetch-2.6.1.tgz#045bd323631f76ed2e2b55573394416b639a0052"
+  integrity sha512-V4aYg89jEoVRxRb2fJdAg8FHvI7cEyYdVAh94HH0UIK8oJxUfkjlDQN9RbMx+bEjP7+ggMiFRprSti032Oipxw==
+
 node-pre-gyp@^0.13.0:
   version "0.13.0"
   resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.13.0.tgz#df9ab7b68dd6498137717838e4f92a33fc9daa42"