Ci improvements - Githubissues

This pull request does the following:

Increases swap space - see discussion at https://leanprover.zulipchat.com/#narrow/stream/267928-condensed-mathematics/topic/The.20elephant.20in.20the.20room;
Causes the build step to fail if the build fails - previously it could appear to succeed and the problem would show up later; and
Records some extra debugging info during the build.

leanprover-community / lean-liquid