✨ Adds user model.

 #1

data/models/usersModel.js

@@ -0,0 +1,30 @@
+const db = require("../dbConfig");
+
+module.exports = {
+  add,
+  find,
+  findBy,
+  findById
+};
+
+async function find() {
+  return await db("users").select("id", "username", "password");
+}
+
+async function findBy(filter) {
+  return await db("users")
+    .where(filter)
+    .first();
+}
+
+async function add(user) {
+  const ids = await db("users").insert(user, "id");
+  const [id] = ids;
+  return findById(id);
+}
+
+async function findById(id) {
+  return await db("users")
+    .where({ id })
+    .first();
+}