Add diffutils to devshell.

Author: brocaar

Dockerfile-devel

@@ -29,9 +29,10 @@ RUN apt-get update && apt-get install --no-install-recommends --no-install-sugge
     'curl' \
     'quilt' \
     'nano' \
+    'diffutils' \
   && \
   rm -f -r '/var/lib/apt/' && \
   rm -f -r '/var/cache/apt/' && \
   useradd -m -s '/bin/bash' -U 'buildbot'
 
-USER buildbot
+USER buildbot