alpine: Use easy-rsa in testing branch of alpine

* Simplifes the Dockerfile significantly.
* No need for curl.

Dockerfile

@@ -1,22 +1,18 @@
 # Original credit: https://github.com/jpetazzo/dockvpn
 
-# Leaner build then Ubunutu
+# Leaner build then Ubuntu
 FROM alpine:3.2
 
 MAINTAINER Kyle Manna <kyle@kylemanna.com>
 
-RUN apk update && \
-    apk add openvpn iptables curl bash && \
+RUN echo "http://dl-4.alpinelinux.org/alpine/edge/testing/" >> /etc/apk/repositories && \
+    apk add --update openvpn iptables bash easy-rsa && \
+    ln -s /usr/share/easy-rsa/easyrsa /usr/local/bin && \
     rm -rf /tmp/* /var/tmp/* /var/cache/apk/*
 
-RUN mkdir -p /usr/local/share/easy-rsa && cd /usr/local/share/easy-rsa && \
-    curl -L https://github.com/OpenVPN/easy-rsa/archive/v3.0.0.tar.gz | tar xzf - easy-rsa-3.0.0/easyrsa3 && \
-    mv easy-rsa-3.0.0/easyrsa3 . && rmdir easy-rsa-3.0.0 && \
-    ln -s /usr/local/share/easy-rsa/easyrsa3/easyrsa /usr/local/bin
-
 # Needed by scripts
 ENV OPENVPN /etc/openvpn
-ENV EASYRSA /usr/local/share/easy-rsa/easyrsa3
+ENV EASYRSA /usr/share/easy-rsa
 ENV EASYRSA_PKI $OPENVPN/pki
 ENV EASYRSA_VARS_FILE $OPENVPN/vars