Require usage of single quotes for docker -e parameter (otherwise subsitutions do happen)

[Nachtfeuer]

Following problem:

FOO="\${}" spline
...
2018-06-13 15:15:08,595 - spline.components.bash - Running script /tmp/pipeline-script-Kj8mAR.sh
2018-06-13 15:15:08,612 - spline.components.tasks -  | /tmp/pipeline-script-Kj8mAR.sh: line 24: FOO=${}: bad substitution
2018-06-13 15:15:08,612 - spline.components.bash - Exit code has been 1
...

Simple pipeline demo for that issue (as sufficient):

pipeline:
  - stage(demo):
      - tasks(ordered):
        - docker(container):
            script: |
              echo "hello"

[Nachtfeuer]

Solution: -e 'FOO=${}' instead of double quotes!

[Nachtfeuer]

done