Add alerts on all old APIs on both Swarming and Isolate servers.

Add alerts on all old APIs on both Swarming and Isolate servers.

This is in preparation of deleting these APIs. Adding the errors will alert the
admins.

R=vadimsh@chromium.org
BUG=

Committed: https://github.com/luci/luci-py/commit/0071ad11a2ebd0d757e6b8325df81ec2e4f3ec61

[M-A Ruel, 2015-11-17 22:34:50]

I'll commit+deploy this once the all the known clients are updated.

[Vadim Sh., 2015-11-17 22:35:43]

lgtm

chromecompute.appspot.com is using old API. I'll change this today.

[M-A Ruel, 2015-11-24 20:19:05]

On 2015/11/17 22:35:43, Vadim Sh. wrote:
> lgtm
> 
> http://chromecompute.appspot.com is using old API. I'll change this today.

Was it completed? The other blocker is done.

[Vadim Sh., 2015-11-24 20:27:58]

On 2015/11/24 20:19:05, M-A Ruel wrote:
> On 2015/11/17 22:35:43, Vadim Sh. wrote:
> > lgtm
> > 
> > http://chromecompute.appspot.com is using old API. I'll change this today.
> 
> Was it completed? The other blocker is done.

yes, it was completed https://chromereviews.googleplex.com/308217014/

[M-A Ruel, 2015-11-24 20:33:34]

The CQ bit was checked by maruel@chromium.org

[commit-bot: I haz the power, 2015-11-24 20:33:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1457613002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1457613002/1

[commit-bot: I haz the power, 2015-11-24 20:35:49]

Committed patchset #1 (id:1) as
https://github.com/luci/luci-py/commit/0071ad11a2ebd0d757e6b8325df81ec2e4f3ec61