Add rake task for updating branch value on builds

lib/tasks/build_update_branch.rake

@@ -0,0 +1,21 @@
+namespace :build do
+  namespace :migrate do
+    task :branch do
+      require 'travis'
+      Travis::Database.connect
+
+      branches = Hash.new { |h, k| h[k] = [] }
+
+      Build.pushes.includes(:commit).find_in_batches do |builds|
+        builds.each do |build|
+          #next if build.branch
+          branches[build.commit.branch] << build.id
+        end
+      end
+
+      branches.each do |branch, ids|
+        Build.where(id: ids).update_all(branch: branch)
+      end
+    end
+  end
+end