Roll luci-go to 3b028dd0e92999b1cb91f7e67e355baba0378af7.

Roll luci-go to 3b028dd0e92999b1cb91f7e67e355baba0378af7.

The primary reason of this roll is to integrate
c6f88aea99b3bbe020d9235101de402037421569 which retries more on HTTP 404 for
Cloud Endpoints API call.

Add a README.md.

R=vadimsh@chromium.org
BUG=522388
Committed: https://crrev.com/79c8acaa5fc38ef1ef5c37b229179b7f1c80dc9c
Cr-Commit-Position: refs/heads/master@{#355344}

[Vadim Sh., 2015-10-21 18:04:57]

lgtm

[M-A Ruel, 2015-10-21 18:08:14]

The CQ bit was checked by maruel@chromium.org

[commit-bot: I haz the power, 2015-10-21 18:10:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1423493002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1423493002/1

[commit-bot: I haz the power, 2015-10-21 18:21:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-21 18:22:26]

Patchset 1 (id:??) landed as
https://crrev.com/79c8acaa5fc38ef1ef5c37b229179b7f1c80dc9c
Cr-Commit-Position: refs/heads/master@{#355344}