Merge branch 'staging' into 'master'

Merge in staging

See merge request containers/eic_container!14

README.md

@@ -15,9 +15,9 @@ cd eic_container
    modeuefile will be installed to `$PREFIX/../../etc/modulefiles`. 
    You can use the `-v` flag to select the version you want to deploy, or omit the 
    flag if you want to install the master build. The recommended stable 
-   release version is `v2.3.0`.
+   release version is `v2.3.1`.
 ```bash
-./deploy.py -v 2.3.0 <PREFIX>
+./deploy.py -v 2.3.1 <PREFIX>
 ```
 
    Available flags:

VERSION

-2.3.0
+2.3.1

containers/release/Dockerfile.in

@@ -35,6 +35,7 @@ RUN apt-get -yqq update \
         ghostscript \
         gv \
         poppler-utils \
+        parallel \
  && apt-get -yqq autoremove \
  && rm -rf /var/lib/apt/lists/*