* remove json-schemas
* main schema can be removed too
* add .gitignore to schemas folder
* try to explicitly get the new haystack in the rest api tests
* fix workflow again
* fix version string in rest api tests
* add pip freeze
* debug statements in workflow
* -U prevents schema generation
* clean up tests and run earlier
* use change detection
* better naming, skip ES
* more cleanup
* fix job name
* dummy commit to trigger the CI
* mock away the PDF converter
* make the test compatible with 3.7
* removed leftover
* always run the api tests, use a matrix for the OS
* refactor all the tests
* remove outdated dependency
* pylint
* new abstract method
* adjust for older python versions
* rename pipeline file
* address PR comments