Chore: Added tests for contacts_controller (#509)

- Tests for contacts controller
Addresses:  #37

app/views/api/v1/contacts/index.json.jbuilder

@@ -4,7 +4,7 @@ json.payload do
     json.name contact.name
     json.email contact.email
     json.phone_number contact.phone_number
-    json.thumbnail contact.avatar.profile_thumb.url
+    json.thumbnail contact.avatar_url
     json.additional_attributes contact.additional_attributes
   end
 end

app/views/api/v1/contacts/update.json.jbuilder

@@ -3,6 +3,6 @@ json.payload do
   json.name @contact.name
   json.email @contact.email
   json.phone_number @contact.phone_number
-  json.thumbnail @contact.avatar.thumb.url
+  json.thumbnail @contact.avatar_url
   json.additional_attributes @contact.additional_attributes
 end