Add the log stream from docker if build fails

[ludeeus]

Proposed change

This adds more logs when docker builds fails giving add-on devs a chance to see what's wrong with out building locally on their machine with docker.

In addition to the cryptic:

20-11-02 10:11:11 ERROR (SyncWorker_2) [supervisor.docker.addon] Can't build local/amd64-addon-sync:0.4: The command '/bin/ash -o pipefail -c apk add --no-cache jq==223' returned a non-zero code: 1

With this PR it adds the build log as well:

20-11-02 10:11:11 ERROR (SyncWorker_2) [supervisor.docker.addon] Build log: 
Step 1/12 : ARG BUILD_FROM
Step 2/12 : FROM $BUILD_FROM
 ---> b70ac30ea587
Step 3/12 : ENV LANG C.UTF-8
 ---> Using cache
 ---> 21a3a2cca551
Step 4/12 : RUN apk add --no-cache jq==223
 ---> Running in 661ea6b65db9
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/main/x86_64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/v3.12/community/x86_64/APKINDEX.tar.gz
ERROR: unsatisfiable constraints:

  jq-1.6-r1:
    breaks: world[jq=223]
Removing intermediate container 661ea6b65db9

I think this change will be very much welcome by add-on developers.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (which adds functionality to the supervisor)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast supervisor tests)
• Tests have been added to verify that the new code works.

If API endpoints of add-on configuration are added/changed:

• Documentation added/updated for developers.home-assistant.io