simplifies dockerfile

Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM node:8-jessie
 
 WORKDIR /app
 
@@ -14,20 +14,7 @@ ENV TOR_PATH /usr/bin/tor
 
 ENV PATH $PATH:/app/bin 
 
-ADD https://deb.nodesource.com/setup_8.x /tmp/nodejs_install
-
-RUN apt-get update && apt-get -y install dirmngr
-
-RUN gpg --keyserver keys.gnupg.net --recv A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89 && gpg --export A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89 | apt-key add -
-
-RUN echo 'deb http://deb.torproject.org/torproject.org artful main\n\
-\n\
-deb-src http://deb.torproject.org/torproject.org artful main'\
->> /etc/apt/sources.list.d/tor.list
-
-RUN bash /tmp/nodejs_install
-
-RUN apt-get install -y nodejs tor git
+RUN apt-get update && apt-get install -y tor
 
 RUN useradd -ms /bin/bash tor_router