Update edit handlers unit tests
Update edit handlers unit tests

Add more tests. Clean up modified class properties after tests finish.
Replace assertRegexpMatches with assertIn.

wagtail/wagtail,takeflight/wagtail,jordij/wagtail,Klaudit/wagtail,janusnic/wagtail,hamsterbacke23/wagtail,jorge-marques/wagtail,darith27/wagtail,Pennebaker/wagtail,davecranwell/wagtail,dresiu/wagtail,nilnvoid/wagtail,jorge-marques/wagtail,takeshineshiro/wagtail,tangentlabs/wagtail,mikedingjan/wagtail,FlipperPA/wagtail,chimeno/wagtail,wagtail/wagtail,bjesus/wagtail,stevenewey/wagtail,nutztherookie/wagtail,Toshakins/wagtail,mephizzle/wagtail,nilnvoid/wagtail,tangentlabs/wagtail,rsalmaso/wagtail,kurtrwall/wagtail,rsalmaso/wagtail,gogobook/wagtail,nutztherookie/wagtail,benjaoming/wagtail,jnns/wagtail,mjec/wagtail,mixxorz/wagtail,WQuanfeng/wagtail,torchbox/wagtail,hanpama/wagtail,jorge-marques/wagtail,marctc/wagtail,timorieber/wagtail,takeflight/wagtail,100Shapes/wagtail,wagtail/wagtail,JoshBarr/wagtail,nimasmi/wagtail,timorieber/wagtail,WQuanfeng/wagtail,mikedingjan/wagtail,JoshBarr/wagtail,nealtodd/wagtail,gogobook/wagtail,nimasmi/wagtail,mephizzle/wagtail,dresiu/wagtail,gasman/wagtail,benemery/wagtail,rsalmaso/wagtail,serzans/wagtail,timorieber/wagtail,mephizzle/wagtail,FlipperPA/wagtail,benjaoming/wagtail,stevenewey/wagtail,marctc/wagtail,bjesus/wagtail,chimeno/wagtail,100Shapes/wagtail,m-sanders/wagtail,wagtail/wagtail,Tivix/wagtail,taedori81/wagtail,takeflight/wagtail,mixxorz/wagtail,jordij/wagtail,iho/wagtail,janusnic/wagtail,KimGlazebrook/wagtail-experiment,jnns/wagtail,kaedroho/wagtail,bjesus/wagtail,JoshBarr/wagtail,wagtail/wagtail,janusnic/wagtail,lojack/wagtail,rjsproxy/wagtail,iansprice/wagtail,darith27/wagtail,rjsproxy/wagtail,Klaudit/wagtail,willcodefortea/wagtail,taedori81/wagtail,willcodefortea/wagtail,quru/wagtail,nimasmi/wagtail,nilnvoid/wagtail,willcodefortea/wagtail,kaedroho/wagtail,zerolab/wagtail,chrxr/wagtail,tangentlabs/wagtail,thenewguy/wagtail,KimGlazebrook/wagtail-experiment,WQuanfeng/wagtail,benemery/wagtail,gasman/wagtail,thenewguy/wagtail,hanpama/wagtail,kaedroho/wagtail,serzans/wagtail,gasman/wagtail,takeshineshiro/wagtail,iho/wagtail,kurtw/wagtail,jnns/wagtail,KimGlazebrook/wagtail-experiment,mjec/wagtail,mikedingjan/wagtail,rv816/wagtail,benjaoming/wagtail,hamsterbacke23/wagtail,inonit/wagtail,zerolab/wagtail,taedori81/wagtail,hanpama/wagtail,nrsimha/wagtail,davecranwell/wagtail,takeflight/wagtail,nealtodd/wagtail,darith27/wagtail,rjsproxy/wagtail,dresiu/wagtail,nealtodd/wagtail,lojack/wagtail,nilnvoid/wagtail,thenewguy/wagtail,benemery/wagtail,rsalmaso/wagtail,takeshineshiro/wagtail,takeshineshiro/wagtail,FlipperPA/wagtail,gogobook/wagtail,gogobook/wagtail,Pennebaker/wagtail,zerolab/wagtail,inonit/wagtail,chrxr/wagtail,mayapurmedia/wagtail,marctc/wagtail,bjesus/wagtail,KimGlazebrook/wagtail-experiment,janusnic/wagtail,JoshBarr/wagtail,lojack/wagtail,dresiu/wagtail,rv816/wagtail,iansprice/wagtail,dresiu/wagtail,Tivix/wagtail,quru/wagtail,nimasmi/wagtail,thenewguy/wagtail,benjaoming/wagtail,willcodefortea/wagtail,kurtrwall/wagtail,stevenewey/wagtail,nrsimha/wagtail,kurtw/wagtail,stevenewey/wagtail,nealtodd/wagtail,timorieber/wagtail,chimeno/wagtail,Pennebaker/wagtail,zerolab/wagtail,marctc/wagtail,taedori81/wagtail,serzans/wagtail,FlipperPA/wagtail,Tivix/wagtail,nrsimha/wagtail,iho/wagtail,rjsproxy/wagtail,chrxr/wagtail,hamsterbacke23/wagtail,Klaudit/wagtail,WQuanfeng/wagtail,thenewguy/wagtail,rv816/wagtail,mikedingjan/wagtail,iansprice/wagtail,mayapurmedia/wagtail,gasman/wagtail,jnns/wagtail,mayapurmedia/wagtail,iho/wagtail,m-sanders/wagtail,davecranwell/wagtail,Tivix/wagtail,kurtw/wagtail,serzans/wagtail,100Shapes/wagtail,davecranwell/wagtail,quru/wagtail,inonit/wagtail,jordij/wagtail,nutztherookie/wagtail,torchbox/wagtail,chimeno/wagtail,darith27/wagtail,kurtrwall/wagtail,hanpama/wagtail,taedori81/wagtail,jorge-marques/wagtail,torchbox/wagtail,benemery/wagtail,Toshakins/wagtail,Pennebaker/wagtail,mephizzle/wagtail,quru/wagtail,tangentlabs/wagtail,Klaudit/wagtail,mixxorz/wagtail,hamsterbacke23/wagtail,jorge-marques/wagtail,kaedroho/wagtail,rv816/wagtail,Toshakins/wagtail,nutztherookie/wagtail,gasman/wagtail,chrxr/wagtail,iansprice/wagtail,nrsimha/wagtail,mixxorz/wagtail,m-sanders/wagtail,mayapurmedia/wagtail,mjec/wagtail,chimeno/wagtail,zerolab/wagtail,mjec/wagtail,Toshakins/wagtail,rsalmaso/wagtail,m-sanders/wagtail,torchbox/wagtail,jordij/wagtail,kaedroho/wagtail,kurtrwall/wagtail,kurtw/wagtail,mixxorz/wagtail,inonit/wagtail