server: noop in migration when there's nothing to do

server/lib/twenty/server/migration/1_create_projects.rb

@@ -2,6 +2,7 @@
 
 Sequel.migration do
   up do
+    next if table_exists?(:projects)
     create_table(:projects) do
       primary_key :id
       String :name, null: false

server/lib/twenty/server/migration/2_create_tasks.rb

@@ -2,6 +2,7 @@
 
 Sequel.migration do
   up do
+    next if table_exists?(:tasks)
     create_table(:tasks) do |t|
       primary_key :id
       String :title, null: false

server/lib/twenty/server/migration/3_add_color_to_projects.rb

@@ -1,7 +1,13 @@
 # frozen_string_literal: true
 
 Sequel.migration do
+  column_exists = ->(table, column) do
+    schema = Twenty.connection.schema(table)
+    schema.find { |(key,_)| key == column }
+  end
+
   up do
+    next if column_exists.call(:projects, :color)
     default = Twenty::Mixin::Colorable.random_color
     add_column :projects, :color, :string, null: false, default:
   end