ALBS-173: Make first successful build

- It's enable lazy unmounting bind mounts
- The amount of retries is increased from 3 to 10
- The value of retry sleep is increased from 1.0 to 5

src/pylorax/imgutils.py

@@ -503,7 +503,7 @@ class DracutChroot(object):
 
         # cleanup bind mounts
         for _, d in self.bind:
-            umount(self.root + d)
+            umount(self.root + d, lazy=True, maxretry=10, retrysleep=5)
 
     def Run(self, args):
         runcmd(["dracut"] + args, root=self.root)