Convert to ts (#386)

Converts email validator and  Avatar component to typescript

frontend/components/forms/validators/valid_email/index.js

@@ -1,9 +1 @@
-const EMAIL_REGEX = /\S+@\S+\.\S+/;
-
-export default (email) => {
-  if (EMAIL_REGEX.test(email)) {
-    return true;
-  }
-
-  return false;
-};
+export default from './valid_email.ts';

frontend/components/forms/validators/valid_email/valid_email.ts

@@ -0,0 +1,9 @@
+const EMAIL_REGEX = /\S+@\S+\.\S+/;
+
+export default (email: string): boolean => {
+  if (EMAIL_REGEX.test(email)) {
+    return true;
+  }
+
+  return false;
+};