revert docker changes

Author: klarkc

Dockerfile

@@ -2,10 +2,8 @@ FROM node:8.2.1-alpine
 
 ENV GTT_VERSION 1.7.39
 
-WORKDIR /pwd
-
 RUN yarn global add --prefix /usr/local "gitlab-time-tracker@$GTT_VERSION"
 
-VOLUME ["/root", "/pwd"]
+VOLUME ["/root"]
 ENTRYPOINT ["gtt"]
 CMD ["--help"]