Force ASCII-8BIT since the default encoding for scripts is UTF-8 in 2.0.

See https://www.ruby-lang.org/en/news/2013/02/24/ruby-2-0-0-p0-is-released/
Merge pull request #218 from jrafanie/force_binary_encoding_due_to_utf8_default_in_ruby_2_0

Force ASCII-8BIT since the default encoding for scripts is UTF-8 in 2.0.