Resolve "bugfix test failures"

Closes #92

See merge request !65

Resolve "Add function to install ogs and python dependencies"

Closes #90

See merge request !64

[doc] separate vignette building into two steps

See merge request !62

    original vignettes will now be used as src for
    prebuilding vignettes in rmd format
    the prebuild vignettes can than be created
    with r cmd build, solves problems on cran

Resolve "[bugfix] coverage computation in ci test pipeline"

Closes #83

See merge request !61