fix(front): Add integration type mapping for :GITLAB (#345)

## 📝 Description

renderedtext/project-tasks#2413 While working
on this task I noticed a 500 page while trying to create a new project.
This should solve it

## ✅ Checklist
- [ ] I have tested this change
- [ ] This change requires documentation update

Author: VeljkoMaksimovic

front/lib/front/models/forkable.ex

@@ -219,6 +219,7 @@ defmodule Front.Models.Forkable do
   def map_integration_types(:GITHUB_APP), do: "github"
   def map_integration_types(:GITHUB_OAUTH_TOKEN), do: "github"
   def map_integration_types(:BITBUCKET), do: "bitbucket"
+  def map_integration_types(:GITLAB), do: "gitlab"
 
   def map_integration_types(integration_type) do
     integration_type