Update 1.13.0

[fireflycons]

Updates to 1.13.0 version

[fireflycons]

I've run through the edited instructions a couple of times and all seems reasonable. Made quite a few changes to aid copy-paste from code blocks to the terminal, also

• Updated to Ubuntu Focal Fossa
• Added missing section Running commands in parallel with tmux in prerequisites section that was linked but didn't exist.
• Added commands to put master-1 ssh key into master-1 authorized_keys (there was a student question on why does the scp to master-1 fail with public key auth error).
• Added missing Next links in first couple of pages
• Corrected some spelling and grammar
• Corrected an issue where /var/lib/kubernetes doesn't exist early on and carried through the other labs where it should now exist.
• Added instructions on how to suspend the lab and resume later
• Updated doc links in tls bootstrapping

In the Smoke Test section, for exec and logs I get the following

x509: certificate signed by unknown authority

I haven't changed any of the certificate-authority instructions. Not sure what I missed.

[fireflycons]

Also I noted in tls bootstrapping that worker-2 CSR was auto approved. Went through the whole thing twice when verifying my changes.

[fireflycons]

Closing this, as we're doing 1.24 now.