Add tests for is_watching method
Add tests for is_watching method

Currently they fail for uv-based watcher.
magus424/powerline,magus424/powerline,Luffin/powerline,IvanAli/powerline,bezhermoso/powerline,s0undt3ch/powerline,darac/powerline,russellb/powerline,seanfisk/powerline,DoctorJellyface/powerline,firebitsbr/powerline,magus424/powerline,S0lll0s/powerline,s0undt3ch/powerline,russellb/powerline,xxxhycl2010/powerline,dragon788/powerline,kenrachynski/powerline,lukw00/powerline,xfumihiro/powerline,bezhermoso/powerline,kenrachynski/powerline,Liangjianghao/powerline,wfscheper/powerline,QuLogic/powerline,seanfisk/powerline,EricSB/powerline,xxxhycl2010/powerline,areteix/powerline,prvnkumar/powerline,russellb/powerline,DoctorJellyface/powerline,bartvm/powerline,cyrixhero/powerline,lukw00/powerline,blindFS/powerline,blindFS/powerline,prvnkumar/powerline,QuLogic/powerline,QuLogic/powerline,IvanAli/powerline,wfscheper/powerline,seanfisk/powerline,Luffin/powerline,Liangjianghao/powerline,wfscheper/powerline,bezhermoso/powerline,IvanAli/powerline,junix/powerline,S0lll0s/powerline,s0undt3ch/powerline,xfumihiro/powerline,dragon788/powerline,xxxhycl2010/powerline,bartvm/powerline,S0lll0s/powerline,kenrachynski/powerline,cyrixhero/powerline,dragon788/powerline,areteix/powerline,EricSB/powerline,darac/powerline,xfumihiro/powerline,prvnkumar/powerline,junix/powerline,Luffin/powerline,Liangjianghao/powerline,cyrixhero/powerline,DoctorJellyface/powerline,blindFS/powerline,areteix/powerline,firebitsbr/powerline,lukw00/powerline,firebitsbr/powerline,darac/powerline,bartvm/powerline,EricSB/powerline,junix/powerline