Add UserContext unit test for signup

package.json

@@ -19,6 +19,7 @@
     "start": "react-scripts start",
     "build": "react-scripts build",
     "test": "react-scripts test",
+    "test:debug": "react-scripts --inspect-brk test --runInBand --no-cache",
     "eject": "react-scripts eject"
   },
   "eslintConfig": {
@@ -41,5 +42,8 @@
   },
   "engines": {
     "node": "12.20.1"
+  },
+  "devDependencies": {
+    "react-test-renderer": "^17.0.1"
   }
 }