cz.archive.ubuntu.com is down, use archive.ubuntu.com
cz.archive.ubuntu.com is down, use archive.ubuntu.com

Build fails because cz.archive.ubuntu.com returns 403 Forbidden:

sudo apt-get update -qq
W: Failed to fetch http://cz.archive.ubuntu.com/ubuntu/dists/vivid/main/binary-amd64/Packages  403  Forbidden
W: Failed to fetch http://cz.archive.ubuntu.com/ubuntu/dists/vivid/main/binary-i386/Packages  403  Forbidden
E: Some index files failed to download. They have been ignored, or old ones used instead.

Use top-level archive.ubuntu.com instead.

smarkets/smk_python_sdk