fix: typo

Dockerfile

-FROM node:7
+FROM node:7.9
 MAINTAINER PubSweet Team <richard@coko.foundation>
 
 # add our user and group first to make sure their IDs get assigned consistently, regardless of whatever dependencies get added
@@ -52,6 +52,7 @@ RUN yarn config set yarn-offline-mirror ./npm-packages-offline-cache && \
 RUN git config --global user.email "test@testing.com" && \
     git config --global user.name "Fakey McFakerson"
 
+# We install the dependencies for all repos and then remove them in order to leverage yarn's cache when we install in CI
 RUN cd && \
     git clone https://gitlab.coko.foundation/pubsweet/pubsweet-server.git && \
     cd pubsweet-server && \