fix(pip): update location of pip installer

raw.github.com URLs have moved to raw.githubusercontent.com, and
wget was seeing a 301 (Moved Permanently) under the covers. curl
does not automatically follow such a redirect, so the URL change
caused an error for deis/tester, but was benign here.
style(coreos): remove unused systemd template strings
fix(builder): do not check for a Procfile

Some applications do not have a Procfile present before a buildpack
compile step[1]. If a Dockerfile is not present, then the builder
should make the assumption that this app is a buildpack app.

[1]: https://github.com/bacongobbler/heroku-buildpack-jekyll/blob/master/bin/release
refactor(controller): remove duplicate run() method
fix(Makefile): check for errors after controller

This must have been lost in a recent refactor.
Merge pull request #881 from deis/add_check_errors

fix(Makefile): check for errors after controller
Merge pull request #879 from deis/vestigial-templates

style(coreos): remove unused systemd template strings
tests(travis-ci): remove branch restrictions for test runs

We previously restricted travis-ci.org builds to just the `master`
and `release` branches, but that isn't necessary. To help with
developing new integration tests, have Travis build any Deis branch.
fix(systemd): handle app containers on restarts

This was missed in 66660a4, which allows app containers to be
properly restarted on ungraceful host reboots. See the discussion
at #871 for more information.
Merge pull request #872 from deis/remove-containers-on-start

fix(systemd): handle app containers on restarts
docs(contributing): add skip ci tag

You can skip a build on TravisCI by adding the skip ci tag
to the commit message. This formalizes that process in the
documentation.

ref: http://docs.travis-ci.com/user/how-to-skip-a-build/
docs(contributing): split out DCO
fix(test): specify machine IPs

The Rakefile breaks for cloud providers, as we used the HOST
for both the cluster domain and a list of hosts. Since etcd/fleet
now listen exclusively on the `private_ipv4` interface, connecting
on the public domain doesn't work.

This commit adds a new environment variable, `DEIS_TEST_HOSTS`,
to pass in the hosts to the creation of the cluster.
refactor(contrib/rackspace): create private network on Rackspace

Previously, we were creating servers using the default Rackspace
ServiceNet as the private network. This means that they are feasibly
accessible by other servers on that network. This commit ensures
we are creating a new, private network for deis and not connecting
to the ServiceNet any longer.

closes #891
fix(docker): use btrfs inside builder

We have seen mixed usage of aufs and btrfs cause problems before. On
CoreOS, btrfs rules the day, so use that.
Merge pull request #886 from deis/docs-no-ci

docs(contributing): add skip ci tag
fix(ec2): add explicit 100GB root volume

By default the m3 instances (of all types) use an 8GB root volume.
The SSD volume is unused and located at /dev/xvdb. This PR changes
the 8GB root volume to 100GB, providing enough storage for a basic
Deis cluster.

fixes #882
Merge pull request #889 from deis/test_hosts

fix(test): specify machine IPs
fix(client): return non-zero on errors

Some commands were inconsistent and returned 0 when an error
occurred. This makes the client more consistent with errors.

closes #767
refactor(client): remove provider functions

Deis no longer handles provider code, so these functions should not
exist in the client.