Add backend validation to check for lowercase

Docker/.gitignore

@@ -2,4 +2,5 @@
 !build_images.sh
 mongo/data/*
 redis/data/*
-*.env
+*.env
+certbot/*

Server/validation/joi.js

@@ -35,7 +35,17 @@ const registerValidation = joi.object({
     .string()
     .required()
     .pattern(/^[A-Za-z]+$/),
-  email: joi.string().email().required(),
+  email: joi
+    .string()
+    .email()
+    .required()
+    .custom((value, helpers) => {
+      const lowercasedValue = value.toLowerCase();
+      if (value !== lowercasedValue) {
+        return helpers.message("Email must be in lowercase");
+      }
+      return lowercasedValue;
+    }),
   password: joi
     .string()
     .min(8)