Upgrade auth0-js for security concerns

I pinned the specific version because later versions have a bug.

For full details see:
https://nvd.nist.gov/vuln/detail/CVE-2018-7307

CVE-2018-7307
More information
moderate severity
Vulnerable versions: < 9.3.0
Patched version: 9.3.0

The Auth0.js library has a vulnerability affecting versions below 9.3 that allows an attacker to bypass the CSRF check from the state parameter if it's missing from the authorization response, leaving the client vulnerable to CSRF attacks.

package.json

@@ -26,7 +26,7 @@
     "@material-ui/core": "^3.9.2",
     "@material-ui/icons": "^3.0.1",
     "@mozilla-frontend-infra/components": "^2.0.0",
-    "auth0-js": "9.2.3",
+    "auth0-js": "9.6.1",
     "chart.js": "^2.7.3",
     "mitt": "^1.1.3",
     "moment": "^2.23.0",

yarn.lock

@@ -1418,13 +1418,14 @@ atob@^2.1.1:
   resolved "https://registry.yarnpkg.com/atob/-/atob-2.1.2.tgz#6d9517eb9e030d2436666651e86bd9f6f13533c9"
   integrity sha512-Wm6ukoaOGJi/73p/cl2GvLjTI5JM1k/O14isD73YML8StrH/7/lRFgmg8nICZgD3bZZvjwCGxtMOD3wWNAu8cg==
 
-auth0-js@9.2.3:
-  version "9.2.3"
-  resolved "https://registry.yarnpkg.com/auth0-js/-/auth0-js-9.2.3.tgz#f98650a742c83567e887703c5972d0c7275e403d"
-  integrity sha1-+YZQp0LINWfoh3A8WXLQxydeQD0=
+auth0-js@9.6.1:
+  version "9.6.1"
+  resolved "https://registry.yarnpkg.com/auth0-js/-/auth0-js-9.6.1.tgz#908e1bc5e9a7c6f787b019ad53d7688caaa2f48e"
+  integrity sha1-kI4bxemnxveHsBmtU9dojKqi9I4=
   dependencies:
     base64-js "^1.2.0"
-    idtoken-verifier "^1.1.1"
+    idtoken-verifier "^1.2.0"
+    js-cookie "^2.2.0"
     qs "^6.4.0"
     superagent "^3.8.2"
     url-join "^1.1.0"
@@ -4417,7 +4418,7 @@ icss-utils@^2.1.0:
   dependencies:
     postcss "^6.0.1"
 
-idtoken-verifier@^1.1.1:
+idtoken-verifier@^1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/idtoken-verifier/-/idtoken-verifier-1.2.0.tgz#4654f1f07ab7a803fc9b1b8b36057e2a87ad8b09"
   integrity sha512-8jmmFHwdPz8L73zGNAXHHOV9yXNC+Z0TUBN5rafpoaFaLFltlIFr1JkQa3FYAETP23eSsulVw0sBiwrE8jqbUg==
@@ -5327,6 +5328,11 @@ jest@^23:
     import-local "^1.0.0"
     jest-cli "^23.6.0"
 
+js-cookie@^2.2.0:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/js-cookie/-/js-cookie-2.2.0.tgz#1b2c279a6eece380a12168b92485265b35b1effb"
+  integrity sha1-Gywnmm7s44ChIWi5JIUmWzWx7/s=
+
 js-levenshtein@^1.1.3:
   version "1.1.4"
   resolved "https://registry.yarnpkg.com/js-levenshtein/-/js-levenshtein-1.1.4.tgz#3a56e3cbf589ca0081eb22cd9ba0b1290a16d26e"
@@ -5988,7 +5994,19 @@ miller-rabin@^4.0.0:
   resolved "https://registry.yarnpkg.com/mime-db/-/mime-db-1.37.0.tgz#0b6a0ce6fdbe9576e25f1f2d2fde8830dc0ad0d8"
   integrity sha512-R3C4db6bgQhlIhPU48fUtdVmKnflq+hRdad7IyKhtFj06VPNVdk2RhiYL3UjQIlso8L+YxAtFkobT0VK+S/ybg==
 
-mime-types@^2.1.12, mime-types@~2.1.17, mime-types@~2.1.18, mime-types@~2.1.19:
+mime-db@~1.38.0:
+  version "1.38.0"
+  resolved "https://registry.yarnpkg.com/mime-db/-/mime-db-1.38.0.tgz#1a2aab16da9eb167b49c6e4df2d9c68d63d8e2ad"
+  integrity sha512-bqVioMFFzc2awcdJZIzR3HjZFX20QhilVS7hytkKrv7xFAn8bM1gzc/FOX2awLISvWe0PV8ptFKcon+wZ5qYkg==
+
+mime-types@^2.1.12:
+  version "2.1.22"
+  resolved "https://registry.yarnpkg.com/mime-types/-/mime-types-2.1.22.tgz#fe6b355a190926ab7698c9a0556a11199b2199bd"
+  integrity sha512-aGl6TZGnhm/li6F7yx82bJiBZwgiEa4Hf6CNr8YO+r5UHr53tSTYZb102zyU50DOWWKeOv0uQLRL0/9EiKWCog==
+  dependencies:
+    mime-db "~1.38.0"
+
+mime-types@~2.1.17, mime-types@~2.1.18, mime-types@~2.1.19:
   version "2.1.21"
   resolved "https://registry.yarnpkg.com/mime-types/-/mime-types-2.1.21.tgz#28995aa1ecb770742fe6ae7e58f9181c744b3f96"
   integrity sha512-3iL6DbwpyLzjR3xHSFNFeb9Nz/M8WDkX33t1GFQnFOllWk8pOrh/LSrB5OXlnlW5P9LH73X6loW/eogc+F5lJg==