Update/unskip checkpoint tests.
Update/unskip checkpoint tests.

The same gold files can apparently be used.

The 2a, 4a, and 8a tests are still skipped for the moment until we add
a command line argument (like --split-ascii) which can be used to
specify that ASCII files should be used instead of binary.

Refs libMesh/libmesh#1409

jessecarterMOOSE/moose,laagesen/moose,lindsayad/moose,sapitts/moose,YaqiWang/moose,bwspenc/moose,jessecarterMOOSE/moose,andrsd/moose,harterj/moose,harterj/moose,jessecarterMOOSE/moose,lindsayad/moose,sapitts/moose,nuclear-wizard/moose,harterj/moose,lindsayad/moose,sapitts/moose,nuclear-wizard/moose,nuclear-wizard/moose,SudiptaBiswas/moose,harterj/moose,andrsd/moose,SudiptaBiswas/moose,permcody/moose,milljm/moose,SudiptaBiswas/moose,bwspenc/moose,dschwen/moose,laagesen/moose,idaholab/moose,sapitts/moose,bwspenc/moose,bwspenc/moose,bwspenc/moose,lindsayad/moose,idaholab/moose,laagesen/moose,permcody/moose,harterj/moose,andrsd/moose,permcody/moose,idaholab/moose,milljm/moose,dschwen/moose,jessecarterMOOSE/moose,milljm/moose,YaqiWang/moose,laagesen/moose,lindsayad/moose,nuclear-wizard/moose,dschwen/moose,jessecarterMOOSE/moose,YaqiWang/moose,YaqiWang/moose,idaholab/moose,milljm/moose,andrsd/moose,SudiptaBiswas/moose,dschwen/moose,permcody/moose,milljm/moose,dschwen/moose,andrsd/moose,idaholab/moose,sapitts/moose,laagesen/moose,SudiptaBiswas/moose