Comment 3 for bug 1658352

From the dpkg terminal log, the error that's occurring is:

  Processing triggers for initramfs-tools (0.103ubuntu4.7) ...
  update-initramfs: Generating /boot/initrd.img-3.13.0-108-generic
  E: /usr/share/initramfs-tools/hooks/casper-memdisk failed with return 1.
  update-initramfs: failed for /boot/initrd.img-3.13.0-108-generic with 1.
  dpkg: error processing package initramfs-tools (--configure):
   subprocess installed post-installation script returned error exit status 1

The casper-memdisk bit should not be necessary; it's likely that issuing the following commands will resolve the problem you're seeing:

sudo dpkg -P casper-memdisk
sudo apt-get install -f
sudo update-grub