Add isMigrationFileValid() to test if a file extension is valid, and conditionally if the file exists
Add isMigrationFileValid() to test if a file extension is valid, and
conditionally if the file exists

winiceo/bolt,bywatersolutions/reports-site,tekjava/bolt,nantunes/bolt,winiceo/bolt,rossriley/bolt,rossriley/bolt,winiceo/bolt,Raistlfiren/bolt,bolt/bolt,one988/cm,richardhinkamp/bolt,joshuan/bolt,skript-cc/bolt,nikgo/bolt,bywatersolutions/reports-site,Raistlfiren/bolt,nantunes/bolt,one988/cm,joshuan/bolt,rarila/bolt,nikgo/bolt,electrolinux/bolt,Eiskis/bolt-base,hannesl/bolt,hugin2005/bolt,rossriley/bolt,winiceo/bolt,kendoctor/bolt,hannesl/bolt,skript-cc/bolt,electrolinux/bolt,hannesl/bolt,tekjava/bolt,hugin2005/bolt,CarsonF/bolt,codesman/bolt,xeddmc/bolt,HonzaMikula/masivnipostele,CarsonF/bolt,Calinou/bolt,Eiskis/bolt-base,HonzaMikula/masivnipostele,nikgo/bolt,codesman/bolt,marcin-piela/bolt,HonzaMikula/bolt,Raistlfiren/bolt,cdowdy/bolt,bywatersolutions/reports-site,bolt/bolt,lenvanessen/bolt,GDmac/bolt,romulo1984/bolt,Calinou/bolt,GawainLynch/bolt,nantunes/bolt,cdowdy/bolt,romulo1984/bolt,GDmac/bolt,skript-cc/bolt,skript-cc/bolt,hannesl/bolt,Raistlfiren/bolt,Eiskis/bolt-base,Calinou/bolt,pygillier/bolt,HonzaMikula/bolt,joshuan/bolt,marcin-piela/bolt,GawainLynch/bolt,romulo1984/bolt,hugin2005/bolt,GawainLynch/bolt,one988/cm,HonzaMikula/masivnipostele,HonzaMikula/bolt,pygillier/bolt,Intendit/bolt,rarila/bolt,marcin-piela/bolt,rarila/bolt,Intendit/bolt,GDmac/bolt,richardhinkamp/bolt,CarsonF/bolt,HonzaMikula/bolt,GDmac/bolt,tekjava/bolt,electrolinux/bolt,bolt/bolt,marcin-piela/bolt,bywatersolutions/reports-site,rossriley/bolt,electrolinux/bolt,Intendit/bolt,lenvanessen/bolt,xeddmc/bolt,CarsonF/bolt,richardhinkamp/bolt,HonzaMikula/masivnipostele,xeddmc/bolt,pygillier/bolt,cdowdy/bolt,kendoctor/bolt,pygillier/bolt,lenvanessen/bolt,romulo1984/bolt,bolt/bolt,Intendit/bolt,joshuan/bolt,one988/cm,kendoctor/bolt,xeddmc/bolt,Calinou/bolt,kendoctor/bolt,lenvanessen/bolt,richardhinkamp/bolt,nantunes/bolt,GawainLynch/bolt,cdowdy/bolt,hugin2005/bolt,codesman/bolt,nikgo/bolt,rarila/bolt,tekjava/bolt,Eiskis/bolt-base,codesman/bolt