Bring back the nightlies

[nolanlawson]

Should we do this with Jenkins, or can Travis give us this? Else I have a couple spare EC2 instances that could build the code around midnight (GMT?) and throw it up on S3.

[daleharvey]

travis can have a script that pushes on every commit to master, just need to figure out the secure env and such

[calvinmetcalf]

we can also publish to npm when we do this as well, (with a prerelease tag and a build number) nightlies are good for the browser but useless in node/browerify

[nolanlawson]

http:https://pouchtest.com/nightly, good enough