Dockerfile: Update pinned versions of alpine and openvpn

alpine: 3.7
openvpn: 2.4.4-r1

Author: bekriebel

Dockerfile

@@ -1,11 +1,11 @@
 # Smallest base image
-FROM alpine:3.6
+FROM alpine:3.7
 
 MAINTAINER Pieter Lange <pieter@ptlc.nl>
 
 RUN echo "http://dl-cdn.alpinelinux.org/alpine/edge/community/" >> /etc/apk/repositories && \
     echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing/" >> /etc/apk/repositories && \
-    apk add --update openvpn=2.4.3-r0 \
+    apk add --update openvpn=2.4.4-r1 \
       bash easy-rsa libintl inotify-tools openvpn-auth-pam google-authenticator pamtester && \
     apk add --virtual temppkg gettext &&  \
     cp /usr/bin/envsubst /usr/local/bin/envsubst && \