message: Switch back to testing on 1.23/1.20, so we know if that breaks.
diff: @@ -38,14 +38,14 @@ matrix:
  - gnuplot
  - os: linux
  env: GNUPLOT=yes
  - rust: 1.25.0
  + rust: 1.23.0
  addons:
  apt:
  packages:
  - gnuplot
  - os: linux
  env: HTML_REPORTS=no GNUPLOT=yes
  - rust: 1.25.0
  + rust: 1.20.0
  addons:
  apt:
  packages:
  