v4.1.8
v4.1.8

        - helloworld: example_kernel_install.sh: example installer
        - helloworld: example_producer_builder.sh: example for builder
        - helloworld: testplans/*/example03-builder: frontend to testplans/*/local
        - helloworld: testplans/*/local: allow specifying precondition producers
        - tapper init: testplans/ subdir now fine-grained
        - tapper init: provide a subdir for producers
        - add notifications for new testrun if requested
        - [TEST] adding notification with testrun
        - [FIX] API docs: new notifications can not be added as a string

tapper/Tapper-Cmd,tapper/Tapper-Cmd