slugbuilder: Use npm-next branch of nodejs buildpack

This installs a newer, less broken version of npm.

https://github.com/heroku/heroku-buildpack-nodejs/compare/v60...fae41898 

Signed-off-by: Jonathan Rudenberg <jonathan@titanous.com>
Merge pull request #583 from flynn/npm-next

slugbuilder: Use npm-next branch of nodejs buildpack
test: Add logging to test/apps/signal

Signed-off-by: Lewis Marshall <lewis@lmars.net>
test: Remove docker backend reference

Signed-off-by: Lewis Marshall <lewis@lmars.net>
test: Dump logs from all booted instances

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Merge pull request #582 from flynn/test-debug

Improve CI debugging
host: Kill jobs if connect timeout expires.

Fixes #565

Signed-off-by: Blaž Hrastnik <blaz.hrast@gmail.com>
Merge pull request #577 from flynn/kill-connect-timeout

host: Kill jobs if connect timeout expires.