[...]
Processing triggers for initramfs-tools (0.122ubuntu8.12) ...
[...]
update-initramfs: deferring update (trigger activated)
Processing triggers for initramfs-tools (0.122ubuntu8.12) ...
update-initramfs: Generating /boot/initrd.img-4.4.0-135-generic
[...]
Preparing to unpack .../initramfs-tools_0.122ubuntu8.14_all.deb ...
Unpacking initramfs-tools (0.122ubuntu8.14) over (0.122ubuntu8.12) ...
[...]
Preparing to unpack .../ca-certificates_20170717~16.04.2_all.deb ...
Unpacking ca-certificates (20170717~16.04.2) over (20170717~16.04.1) ...
[...]
Setting up initramfs-tools (0.122ubuntu8.14) ...
update-initramfs: deferring update (trigger activated)
[...]
Setting up ca-certificates (20170717~16.04.2) ...
[...]
Processing triggers for initramfs-tools (0.122ubuntu8.14) ...
update-initramfs: Generating /boot/initrd.img-4.4.0-135-generic
dpkg: cycle found while processing triggers:
 chain of packages whose triggers are or may be responsible:
  initramfs-tools -> ca-certificates
 packages' pending triggers which are or may be unresolvable:
  ca-certificates: update-ca-certificates
  resolvconf: resolvconf-enable-updates
  initramfs-tools: update-initramfs
dpkg: error processing package ca-certificates (--configure):
 triggers looping, abandoned
Processing triggers for resolvconf (1.78ubuntu7) ...
Processing triggers for initramfs-tools (0.122ubuntu8.14) ...
update-initramfs: Generating /boot/initrd.img-4.4.0-135-generic
Errors were encountered while processing:
 ca-certificates
W: --force-yes is deprecated, use one of the options starting with --allow instead.
E: Sub-process /usr/bin/dpkg returned an error code (1)