Add some more WP recommended PHP modules

Add the 'intl', 'imagick' and 'zip' modules, which are not required
but recommended, and may actually be useful.

docker/build.sh

@@ -18,10 +18,13 @@ PACKAGES="
         libapache2-mod-xsendfile
         libapache2-mod-security2
         modsecurity-crs
-        php-xml
+        php-imagick
+        php-intl
         php-mysql
         php-memcached
         php-mbstring
+        php-xml
+        php-zip
 
         noblogs-cli
 "