Add golang:1.14 tests in CI and fix GitLab source client test
I found a small problem running the unit tests wit Go 1.14 locally, I've added a test step for the latest Go release
There's some breaking change with the stdlib parsing package in Go 1.14 where they escape the character they couldn't parse so from
// in Go <= 1.13
parse %: invalid URL escape \"%\"",
it's now
// Go 1.14
parse \"%\": invalid URL escape \"%\"",
so the tests won't pass on 1.14 without updating the assertion. That's why I'm using Contains
instead of EqualError
in !250 (comment 299124816)
Edited by Jaime Martinez