Add test for GradientComponent kernel (#5631)
Add test for GradientComponent kernel (#5631)

yipenggao/moose,friedmud/moose,SudiptaBiswas/moose,SudiptaBiswas/moose,dschwen/moose,nuclear-wizard/moose,joshua-cogliati-inl/moose,friedmud/moose,jessecarterMOOSE/moose,sapitts/moose,giopastor/moose,backmari/moose,stimpsonsg/moose,mellis13/moose,idaholab/moose,nuclear-wizard/moose,yipenggao/moose,permcody/moose,jessecarterMOOSE/moose,YaqiWang/moose,idaholab/moose,jasondhales/moose,wgapl/moose,wgapl/moose,jiangwen84/moose,laagesen/moose,dschwen/moose,sapitts/moose,permcody/moose,andrsd/moose,YaqiWang/moose,milljm/moose,liuwenf/moose,stimpsonsg/moose,harterj/moose,adamLange/moose,andrsd/moose,Chuban/moose,milljm/moose,bwspenc/moose,bwspenc/moose,adamLange/moose,giopastor/moose,jhbradley/moose,lindsayad/moose,sapitts/moose,jessecarterMOOSE/moose,laagesen/moose,liuwenf/moose,kasra83/moose,jhbradley/moose,laagesen/moose,harterj/moose,milljm/moose,liuwenf/moose,jasondhales/moose,lindsayad/moose,andrsd/moose,YaqiWang/moose,giopastor/moose,milljm/moose,katyhuff/moose,jessecarterMOOSE/moose,liuwenf/moose,kasra83/moose,yipenggao/moose,andrsd/moose,katyhuff/moose,kasra83/moose,liuwenf/moose,Chuban/moose,joshua-cogliati-inl/moose,mellis13/moose,milljm/moose,harterj/moose,stimpsonsg/moose,yipenggao/moose,jiangwen84/moose,harterj/moose,stimpsonsg/moose,idaholab/moose,dschwen/moose,laagesen/moose,permcody/moose,YaqiWang/moose,liuwenf/moose,nuclear-wizard/moose,dschwen/moose,andrsd/moose,bwspenc/moose,jhbradley/moose,kasra83/moose,joshua-cogliati-inl/moose,jiangwen84/moose,wgapl/moose,harterj/moose,idaholab/moose,katyhuff/moose,idaholab/moose,permcody/moose,SudiptaBiswas/moose,Chuban/moose,nuclear-wizard/moose,sapitts/moose,mellis13/moose,bwspenc/moose,backmari/moose,jasondhales/moose,jasondhales/moose,Chuban/moose,lindsayad/moose,adamLange/moose,adamLange/moose,laagesen/moose,SudiptaBiswas/moose,SudiptaBiswas/moose,jhbradley/moose,wgapl/moose,jessecarterMOOSE/moose,dschwen/moose,lindsayad/moose,backmari/moose,bwspenc/moose,friedmud/moose,jiangwen84/moose,giopastor/moose,lindsayad/moose,backmari/moose,joshua-cogliati-inl/moose,friedmud/moose,sapitts/moose,mellis13/moose,katyhuff/moose