Merge branch 'feature/first_order_operators' into 'develop'

added some missing operators and a test for all operators

See merge request !67
Status Job ID Name Coverage
  Test
canceled #7949
debian:10 clang-6-libcpp-17

canceled #7948
debian:10 gcc-8-17

canceled #7950
debian:9 gcc-6-14

canceled #7951
ubuntu:18.04 clang-6-17