Dockerfile.build in puma-daemon-0.3.2 vs Dockerfile.build in puma-daemon-0.5.0

@@ -15,10 +15,10 @@
 #    
 #    # Test encryption:
 #    $ encrypt word
 #    
 
-FROM ubuntu:latest
+FROM ubuntu:kinetic
 
 RUN apt-get update -y && \
     apt-get install -yqq \
     build-essential \
     git \