Adding missing ENV variables for Centos 7 image (#3617)

Author: nicknezis

docker/dist/Dockerfile.dist.centos7

@@ -17,6 +17,8 @@
 
 FROM centos:centos7
 
+ENV LC_ALL en_US.utf8
+
 RUN yum -y install epel-release \
     && yum -y update \
     && yum -y install \
@@ -30,6 +32,8 @@ RUN yum -y install epel-release \
     which \
     && yum clean all
 
+ENV JAVA_HOME /usr/
+
 ADD artifacts /heron
 
 WORKDIR /heron