Install `imagemagick` and `php5-imagick`for use with Drupal

[mccrodp]

Hi Rob,

I noticed that these modules were missing in Dockie when I bumped into this issue on all of my docker environments using the docker-compose-drupal setup: RobLoach/docker-compose-drupal#6

Would it be possible to get these into the Dockie image? Thanks!

[RobLoach]

Seem like good additions to have. Think just the apt-gets do it?

[mccrodp]

Yep, apt-gets get them alright. Didn't solve my linked issue unfortunately, but surely a factor!

[mccrodp]

apt-get install postfix - another good one :)