Docker build fails on ARMv7.

[lightvil]

I tried building an image on my ODROID-XU4(armv7).
Docker build failed with the message saying
"docker arm no matching manifest for unknown in the manifest list entries".

It seems that alpine:3.4 has no image for armv7.
Changing "FROM alpine:3.4" to "FROM alpine:latest" results in a successful build.

How about changing alpine tag to 3.7 or later version?

Thank you for your great work.