Fix vitessdriver.Open example

[teejae]

Current docs are out of date and do not match the signature of vitessdriver.Open.

[enisoc]

LGTM

[teejae]

Not sure why the unit/Build fails.

[morgo]

Not sure why the unit/Build fails.

Fetched 52.4 MB in 2s (26.4 MB/s)
E: Failed to fetch http://azure.archive.ubuntu.com/ubuntu/pool/main/p/pulseaudio/libpulse0_11.1-1ubuntu7.2_amd64.deb  404  Not Found [IP: 52.177.174.250 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
##[error]Process completed with exit code 100.

Unit failed in fetching dependencies. We don't run apt-get update currently, and assume it is up to date. It looks like it wasn't, since the package has been removed (i.e. there was probably a security update). This is the first time I have seen this happen, but if it's frequent we can add an apt-get update to the script.