Update php7-extensions.yml
Update php7-extensions.yml

Added new extensions: recode, xmlrpc, wddx, pdo_firebird, interbase, enchant and tidy. Also, now use FakePeclRecipe to build readline.
cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci