docker: Reduce Dockerfile image size (#514)

Dockerfile

@@ -3,15 +3,15 @@ FROM pelias/baseimage
 
 # downloader apt dependencies
 # note: this is done in one command in order to keep down the size of intermediate containers
-RUN apt-get update && apt-get install -y unzip awscli && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install --no-install-recommends -y unzip awscli && rm -rf /var/lib/apt/lists/*
 
 # change working dir
 ENV WORKDIR /code/pelias/openaddresses
 WORKDIR ${WORKDIR}
 
 # copy package.json first to prevent npm install being rerun when only code changes
 COPY ./package.json ${WORKDIR}
-RUN npm install
+RUN npm install && npm cache clean --force;
 
 # copy code into image
 ADD . ${WORKDIR}