Auto-resolving schema.rb version conflicts on Rails 4.0+

.gitattributes

db/schema.rb merge=railsschema

.gitconfig

[merge "railsschema"]
	name = newer Rails schema version
	driver = "ruby -e '\n\
		system %(git), %(merge-file), %(--marker-size=%L), %(%A), %(%O), %(%B)\n\
		b = File.read(%(%A))\n\
		b.sub!(/^<+ .*\\nActiveRecord::Schema\\.define.version: (\\d+). do\\n=+\\nActiveRecord::Schema\\.define.version: (\\d+). do\\n>+ .*/) do\n\
		  %(ActiveRecord::Schema.define(version: #{[$1, $2].max}) do)\n\
		end\n\
		File.open(%(%A), %(w)) {|f| f.write(b)}\n\
		exit 1 if b.include?(%(<)*%L)'"