fix: use Tini for process management in Docker

For more information on why this is necessary, check out the following
article: https://www.elastic.io/nodejs-as-pid-1-under-docker-images/

Closes #157

Dockerfile

@@ -8,12 +8,12 @@ FROM node:12-alpine
 
 WORKDIR /room-assistant
 
-RUN apk add --no-cache bluez bluez-deprecated libusb avahi-dev bind-tools dmidecode \
+RUN apk add --no-cache bluez bluez-deprecated libusb avahi-dev bind-tools dmidecode tini \
     && setcap cap_net_raw+eip $(eval readlink -f `which node`) \
     && setcap cap_net_raw+eip $(eval readlink -f `which hcitool`) \
     && setcap cap_net_admin+eip $(eval readlink -f `which hciconfig`) \
     && ln -s /usr/local/lib/node_modules/room-assistant/bin/room-assistant.js /usr/local/bin/room-assistant
 COPY --from=build /usr/local/lib/node_modules/room-assistant /usr/local/lib/node_modules/room-assistant
 
-ENTRYPOINT ["room-assistant"]
+ENTRYPOINT ["tini", "--", "room-assistant"]
 CMD ["--digResolver"]