Merge pull request #2422 from Alkarex/docker_ubuntu_19.04

Update Docker to Ubuntu 19.04

Docker/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:18.10
+FROM ubuntu:19.04
 
 ENV TZ UTC
 RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone