docparser: recursively create directories

If we want file a/b/c.h we want to make sure that we create a/ and a/b/
which Dir.mkdir doesn't do for us. Use FileUtils.mkdir_p instead.

Author: carlosmn

lib/docurium/docparser.rb

@@ -1,4 +1,5 @@
 require 'tempfile'
+require 'fileutils'
 require 'ffi/clang'
 include FFI::Clang
 
@@ -17,7 +18,7 @@ def parse_file(orig_filename, files)
       unsaved = files.map do |name, contents|
         full_path = File.join(tmpdir, name)
         dirname = File.dirname(full_path)
-        Dir.mkdir(dirname) unless Dir.exists? dirname
+        FileUtils.mkdir_p(dirname) unless Dir.exists? dirname
         File.new(full_path, File::CREAT).close()
 
         UnsavedFile.new(full_path, contents)