Revert "Add custom ImageMagic version"

This reverts commit e66c362345ce32f1c343b75e185fa3d4173410dc.
Add dotCloud CLI to virtual machine config
Upgrade s3-uploader to v0.5
Add default Librato source as "test"
Bump version to v1.4.2
Add Librato log methods
Close #2 - Measure image processing time
Update Librato image count handling
Bump version to v1.5.0