add user model

Gemfile.lock

@@ -121,8 +121,6 @@ GEM
       multi_xml (>= 0.5.2)
     i18n (1.8.10)
       concurrent-ruby (~> 1.0)
-    jbuilder (2.11.2)
-      activesupport (>= 5.0.0)
     jquery-rails (4.4.0)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
@@ -271,6 +269,8 @@ GEM
       tilt
     selectize-rails (0.12.6)
     semantic_range (3.0.0)
+    shoulda-matchers (5.0.0)
+      activesupport (>= 5.2.0)
     spring (2.1.1)
     sprockets (4.0.2)
       concurrent-ruby (~> 1.0)
@@ -323,7 +323,6 @@ DEPENDENCIES
   graphql
   graphql_playground-rails
   httparty
-  jbuilder (~> 2.7)
   listen (~> 3.3)
   pg (~> 1.1)
   pry-byebug
@@ -335,6 +334,7 @@ DEPENDENCIES
   rubocop-rspec
   rubocop-shopify
   sass-rails (>= 6)
+  shoulda-matchers (~> 5.0)
   spring
   tailwindcss-rails
   turbolinks (~> 5)