for when ubuntu /boot needs more space because it's filled with old images

ubuntu_free_boot_space.sh

# you're in a dark room, it's 2 am, and you're
# updating ubuntu via Software Updater, when you get the error:
# Not enough free disk space on disk '/boot'
# what do you do? try this:

# edit: it seems like this one command accomplishes the same thing as the rest, and removes even more unneeded packages
audo apt-get autoremove

# if that doesn't work for some reason, try the original gist revision's steps:
uname -r
#> a.b.c-d-generic
# that's the current image

dpkg --list 'linux-image*'
#> outputs list of linux images that your computer has kept around

# where a<w, b<x, c<y, d<z:
sudo apt-get remove linux-image-w.x.y-z-generic
#> frees up space on /boot by removing an old image