start-dev.sh appears to be broken

[victorb]

From @magik6k on April 12, 2018 5:7

$ ./start-dev.sh
Sending build context to Docker daemon    428MB
Step 1/4 : FROM jenkins/jenkins:2.112-alpine
 ---> 481b49e06417
Step 2/4 : USER root
 ---> Using cache
 ---> e038f512fd2e
Step 3/4 : RUN apk update && apk add --no-cache docker=1.12.6-r0
 ---> Running in 79abf494c95c
fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz
v3.7.0-149-g46ab307937 [http://dl-cdn.alpinelinux.org/alpine/v3.7/main]
v3.7.0-147-g37d0dabafc [http://dl-cdn.alpinelinux.org/alpine/v3.7/community]
OK: 9051 distinct packages available
fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.7/community/x86_64/APKINDEX.tar.gz
ERROR: unsatisfiable constraints:
  docker-17.12.1-r0:
    breaks: world[docker=1.12.6-r0]
The command '/bin/sh -c apk update && apk add --no-cache docker=1.12.6-r0' returned a non-zero code: 1

Copied from original issue: ipfs-inactive/jenkins#105