updated to alpine 3.10

Updated alpine to 3.8

Merge pull request #6 from pschmitt/alpine-3.7

Update base image to alpine 3.7

Merge pull request #5 from ben-st/patch-2

add add command

Merge pull request #4 from ben-st/patch-1

remove apk cache

Changed the alpine image to official repo. Also set to specific tag

Changed the alpine image to official repo. Also set to specific tag

Changed the alpine image to official repo. Also set to specific tag