feat(contrib): auto-create discovery url in ec2 provision

* The provision-ec2-cluster.sh now creates discovery_url on
  the fly instead of the user needing to create it manually
* The discovery_url is stored in a file /tmp/discoveryurl.txt
* Extra Comments to break down the file into sections.
* Readme section for asking to update discovery_url no longer
  present.
fix for osx sed
Update provision-ec2-cluster.sh
fixed sed command for darwin
typo
Merge branch 'master' of https://github.com/deis/deis
fix(client): use sys.stdout.write for logs

The logs already print out newline characters, so using print()
adds an extra empty line to the log output. Using sys.stdout.write()
removes this empty line.
fix(logger): remove Source and Tag from output

An application's logs should not contain which host it was listed
on. It should only care about the data that is relevant to it.

The Tag field is unused, so this added an extra whitespace to the
log format. Removing it cleans up the logs a bit.
test(logger): add filehandler tests
test(logger): add log message tests
feat(logger): add make test/coverage
test(logger): hook up logger tests to TravisCI
style(gitignore): add coverage.out to gitignore
test(logger): add priority tests
fix(travis): install go cover
Accept ECDSA keys in keys:add

Fixes #1262
Add tests for ECDSA keys
fix(controller/scheduler): only announce 'web' and 'cmd' processes

Currently the nginx routers gets announced all types of processes.
This causes problems as both non-web and web processes are mixed
together by the router. The router should only be serving 'web'
processes for buildpacks or 'cmd' processes for dockerfiles.

This fix stops announcing any processes that does not have '.web'
or '.cmd'.

closes #1256
fix(scheduler/coreos): correct announce container logic for process types

Previously, the logger and proctype comparison logic were incorrect.
fix(scheduler/coreos): have announcer fail if it cannot get a port

Instead of publishing an invalid upstream for the router to use,
we simply check if the port is nil and exit.