Build hanging after "Pulling docker image ruby:2.3 ..."

I have two Jekyll sites and both of their builds now hang every time I push. This is where it gets to:

Running with gitlab-ci-multi-runner 1.8.0-rc.1 (1fd3fd4)
Using Docker executor with image ruby:2.3 ...
Pulling docker image ruby:2.3 ...

I’ve reset back to a commit that passed and it’s still hanging, max so far is 30 minutes before I tried again.

Here’s the first one, that I know has passed before and shouldn’t fail. Here’s the second.

This seems to have resolved itself, the builds are passing. It took a really long time.

Build details
Duration: 61 minutes 18 seconds
Finished: 5 minutes ago
Runner: #13977

Is this because I’ve used all of the free resource I have? Would paying to upgrade fix this?