Updated all the examples' YAML files to use the new periodic flag.

examples/AgoraDisk/agora_disk.yml

examples/AgoraDisk/getIC.sh

examples/AgoraDisk/getSolution.sh

examples/AgoraDisk/run.sh

examples/ConstantCosmoVolume/constant_volume.yml

examples/CoolingBox/coolingBox.yml

examples/CoolingHalo/cooling_halo.yml

examples/CoolingHalo/makeIC.py

examples/CoolingHalo/makeIC_random_box.py

examples/CoolingHaloWithSpin/cooling_halo.yml

examples/CoolingHaloWithSpin/makeIC.py

examples/CoolingHaloWithSpin/makeIC_random_box.py

examples/DiscPatch/GravityOnly/disc-patch.yml

examples/DiscPatch/GravityOnly/makeIC.py

examples/DiscPatch/HydroStatic/disc-patch-icc.yml

examples/DiscPatch/HydroStatic/disc-patch.yml

examples/DiscPatch/HydroStatic/makeIC.py

examples/DiscPatch/HydroStatic_1D/disc-patch-icc.yml

examples/DiscPatch/HydroStatic_1D/makeIC.py

examples/DwarfGalaxy/dwarf_galaxy.yml