Added Dockerfile

Dockerfile for image in which the app is build.

Dockerfile

+FROM alpine:edge
+
+LABEL maintainer="Armin Co <armin.co@hs-bochum.de"
+
+# copy mumble-web repository into docker image
+COPY ./mumble-web /home/node
+
+# install git and npm
+RUN apk add --no-cache git npm 
+
+# "install" mumble-web
+RUN cd /home/node   && \
+    npm install     && \
+    npm run build   && \
+    npm audit fix   && \
+    npm audit