MAINT: update runtests.py node id example for pytest usage
MAINT: update runtests.py node id example for pytest usage

* there is a slightly different syntax for specific test selection
in pytest vs. nose; update the syntax of the example in runtests.py
to match pytest

mhvk/numpy,abalkin/numpy,simongibbons/numpy,madphysicist/numpy,MSeifert04/numpy,endolith/numpy,ahaldane/numpy,mattip/numpy,MSeifert04/numpy,gfyoung/numpy,ahaldane/numpy,MSeifert04/numpy,shoyer/numpy,grlee77/numpy,jakirkham/numpy,jakirkham/numpy,charris/numpy,grlee77/numpy,pdebuyl/numpy,madphysicist/numpy,numpy/numpy,pbrod/numpy,mattip/numpy,simongibbons/numpy,grlee77/numpy,grlee77/numpy,rgommers/numpy,ahaldane/numpy,simongibbons/numpy,seberg/numpy,jorisvandenbossche/numpy,abalkin/numpy,mhvk/numpy,WarrenWeckesser/numpy,pbrod/numpy,gfyoung/numpy,ahaldane/numpy,endolith/numpy,pbrod/numpy,WarrenWeckesser/numpy,pizzathief/numpy,anntzer/numpy,numpy/numpy,pbrod/numpy,pdebuyl/numpy,seberg/numpy,endolith/numpy,ahaldane/numpy,madphysicist/numpy,gfyoung/numpy,pizzathief/numpy,pizzathief/numpy,mattip/numpy,mhvk/numpy,shoyer/numpy,shoyer/numpy,numpy/numpy,jorisvandenbossche/numpy,mhvk/numpy,WarrenWeckesser/numpy,simongibbons/numpy,jorisvandenbossche/numpy,shoyer/numpy,madphysicist/numpy,pizzathief/numpy,mhvk/numpy,jorisvandenbossche/numpy,jorisvandenbossche/numpy,madphysicist/numpy,charris/numpy,seberg/numpy,grlee77/numpy,anntzer/numpy,jakirkham/numpy,shoyer/numpy,MSeifert04/numpy,endolith/numpy,seberg/numpy,MSeifert04/numpy,pdebuyl/numpy,rgommers/numpy,WarrenWeckesser/numpy,simongibbons/numpy,charris/numpy,pbrod/numpy,abalkin/numpy,rgommers/numpy,jakirkham/numpy,anntzer/numpy,anntzer/numpy,mattip/numpy,rgommers/numpy,charris/numpy,WarrenWeckesser/numpy,numpy/numpy,jakirkham/numpy,pizzathief/numpy,pdebuyl/numpy