Remove libherb from Steepfile

Author: timkaechele

Steepfile

@@ -12,8 +12,6 @@ target :lib do
   library "tempfile"
 
   ignore "lib/herb/cli.rb"
-  ignore "lib/herb/libherb.rb"
-  ignore "lib/herb/libherb"
   ignore "lib/herb/project.rb"
   ignore "lib/herb/engine/error_formatter.rb"
 end