Update Dockerfile.aarch64

Changed deprecated image & wrong git-lfs architecture

Author: alexaladov-codefresh

Dockerfile.aarch64

@@ -1,10 +1,10 @@
-FROM multiarch/alpine:aarch64-v3.5
+FROM arm64v8/alpine:3.7
 RUN apk add --no-cache git bash
 
 # install git-lfs
 RUN apk add --no-cache --virtual deps openssl && \
-    wget -qO- https://github.com/git-lfs/git-lfs/releases/download/v2.3.4/git-lfs-linux-amd64-2.3.4.tar.gz | tar xz && \
-    mv git-lfs-*/git-lfs /usr/bin/ && \
+    wget -qO- https://github.com/git-lfs/git-lfs/releases/download/v2.6.1/git-lfs-linux-arm64-v2.6.1.tar.gz | tar xz && \
+    mv git-lfs /usr/bin/ && \
     rm -rf git-lfs-* && \
     git lfs install && \
     apk del deps