include xdebug

[bradfordcondon]

I'm trying to add code coverage integration, which means having xdebug in the docker container where we run tripal.

NAL-i5K/tripal_eutils#76

    && yum install -y mod_php php-mcrypt php-mbstring php-json php-posix php-pgsql \
      				  php-pdo php-xml php-curl php-gd supervisor sudo \
      				  patch which

im looking around, how about just sudo yum install php-pecl-xdebug.x86_64