create bottle for php55-memcached
create bottle for php55-memcached

Closes #1979.

Signed-off-by: Andy Blyler <e3579b1e47f273529f0f929453e939a68ede9fd1@blyler.cc>

dguyon/homebrew-php,ablyler/homebrew-php,philcook/homebrew-php,mkalkbrenner/homebrew-php,TomK/homebrew-php