Fix Github Import Failing (#79)

* initial commit for Fix Github Import Failing

* fix deletion of tasks

* remove duplicate name

app/models/task.rb

@@ -21,6 +21,7 @@ class Task < ApplicationRecord
 
   has_many :task_users, dependent: :delete_all
   has_many :users, through: :task_users
+  has_many :time_entries, dependent: :nullify
 
   class << self
     def sync_with_github