picks up fixes of golang/go#18861

[shawnzhu]

Problem

We've seen lots of errors from Travis worker like this:

textPayload: "time="2017-03-14T19:10:57Z" level=error msg="couldn't run script, attempting requeue" completed=false err="couldn't connect to SSH server: couldn't connect to SSH server: ssh: handshake failed: ssh: unexpected message type 3 (expected one of [6])"

the build will finally work after requeue build request several times.

I found a fix from golang/go#18861 and that fix stays on master since Feb 8.

[igorwwwwwwwwwwwwwwwwwwww]

Nice find!

Our dependencies are managed via gvt, and vendored. So running gvt update golang.org/x/crypto/ssh to update vendor/manifest should fix this in a way that works with how we build worker.

[sarahhodne]

Thank you for this! Like @igorwwwwwwwwwwwwwwwwwwww mentioned, we're using gvt to manage our dependencies, so I opened a new PR that updates it there instead at #292. Closing this in favor of that PR.