php70-amqp: add amqp for PHP7
php70-amqp: add amqp for PHP7

Closes #2530.

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

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