Add logic to update submodules and licenses

script/licensed

@@ -4,6 +4,7 @@
 
 require "bundler/setup"
 require "licensed/cli"
+require "optparse"
 
 module Licensed
   module Source
@@ -32,7 +33,14 @@ module Licensed
   end
 end
 
-source = Licensed::Source::Filesystem.new("vendor/grammars/*/", type: "grammar")
+module_path = nil
+OptionParser.new do |opts|
+  opts.on("-mPATH", "--module=PATH", "Cache license file for specific grammar") do |p|
+    module_path = p
+  end
+end.parse!
+
+source = Licensed::Source::Filesystem.new(module_path || "vendor/grammars/*/", type: "grammar")
 config = Licensed::Configuration.new
 config.sources << source
 
@@ -43,4 +51,5 @@ else
 end
 
 command.run
+`git checkout -- vendor/licenses/grammar/` if module_path
 exit command.success?