Can't install local addons

Hi,
i just installed hass.io installed a few addons from repo (mosquitto,samba,ssh) - works fine. The problem is that when I want to run my own addond locally a get following error:

17-10-06 20:18:14 INFO (SyncWorker_19) [hassio.dock.addon] Start build local/armhf-addon-test:0.1
17-10-06 20:18:17 ERROR (MainThread) [aiohttp.server] Error handling request
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/aiohttp/web_protocol.py", line 422, in start
    resp = yield from self._request_handler(request)
  File "/usr/lib/python3.6/site-packages/aiohttp/web.py", line 306, in _handle
    resp = yield from handler(request)
  File "/usr/lib/python3.6/site-packages/hassio/api/util.py", line 31, in wrap_api
    answer = await method(api, *args, **kwargs)
  File "/usr/lib/python3.6/site-packages/hassio/api/addons.py", line 176, in install
    addon.install(version=version), loop=self.loop)
  File "/usr/lib/python3.6/site-packages/hassio/addons/addon.py", line 467, in install
    if not await self.docker.install(version):
  File "/usr/lib/python3.6/site-packages/hassio/dock/util.py", line 18, in wrap_api
    return await method(api, *args, **kwargs)
  File "/usr/lib/python3.6/concurrent/futures/thread.py", line 55, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/lib/python3.6/site-packages/hassio/dock/addon.py", line 198, in _install
    return self._build(tag)
  File "/usr/lib/python3.6/site-packages/hassio/dock/addon.py", line 211, in _build
    image = self.docker.images.build(**build_env.get_docker_args(tag))
  File "/usr/lib/python3.6/site-packages/docker/models/images.py", line 175, in build
    raise BuildError(chunk['error'])
docker.errors.BuildError: oci runtime error: container_linux.go:263: starting container process caused "exec: \"/bin/sh\": stat /bin/sh: no such file or directory"

Here are my source files

run.sh

#!/bin/bash
set -e

echo "Hello world!"

Dockerfile

ARG BUILD_ARG
FROM $BUILD_FROM

# Add env
ENV LANG C.UTF-8

# Setup base
RUN apk add --no-cache jq

# Copy data
COPY run.sh /
RUN chmod a+x /run.sh

CMD [ "/run.sh" ]

config.json

{
  "name": "my test",
  "version": "0.1",
  "slug": "test",
  "description": "test",
  "startup": "before",
  "boot": "auto",
  "arch": ["armhf"],
  "options": {},
  "schema": {}
}

Supervisor: 0.68
Host OS: Control version: 1.1
HA: 0.54

What is the problem?

I am trying to install local addons. I have them in a subfolder under addons but am not sure how to install the addon?