base functionality to create aws resources

allow for bootstrapping of separate CoreOS etcd nodes

clean conditions into docker templates

Add scale-up for etcd cluster

Fix order in restart kubelet to fix systemd reload

Systemd reload before reload kubelet was failing because its definition was before "restart kubelet". Its definition should be after the notify hook.

* Set ETCD_INITIAL_CLUSTER_STATE from `new` to `existing`,
because parameter `new` makes sense only on cluster assembly
stage.
* If cluster exists and current node is not a part
of the cluster, add it with command `etcdctl add member name url`.

Closes kubespray/kargo/#270

example env allow insecure-registry

Many use cases of k8s involve running a local
registry, chances are the person running this
will learn the hard way that they need to allow
insecure registry on the `kube_service_addresses`
network.

We should just default to settings this in
`inventory/group_vars/all.yml` to help reduce
potential friction for first time users.

resolves coreos nodes not setting up docker proxies

provides initial docker options support

removed os restriction for coreos

Dropped a link for people to self-invite to slack channel

turn adduser/download roles into meta roles

This should make things a little more composable,
by making these roles meta roles that perform no
actions by default we allow each role to own its own
resources.

set `--advertise-address` for kube api-server

Kubernetes API server has an option:

```
--advertise-address=<nil>: The IP address on which to advertise the apiserver to members of the cluster. This address must be reachable by the rest of the cluster. If blank, the --bind-address will be used. If --bind-address is unspecified, the host's default interface will be used.
```

kargo does not set --bind-address, thus it binds to eth0, in vagrant and similar
environments this causes issues because nodes cannot talk to eachother over eth0.

This sets `--advertise-address` to `ip` if its set, otherwise the default behavior
of is persisted by using `ansible_default_ipv4.address`.

set vm box to be hashicorp hosted trusty

using a shared folder can cause race conditions for the download
role as it tries to download files on all the nodes to the same
shared path.  This adds a flag to run the tasks in the download
role on just one node.

I accidently left in the old download URL for coreos
even after I switched the box name to be ubuntu, it
worked fine for me because I already had that box
locally so it didn't try to download.  This should
resolve this by using the official bento/ubuntu-14.04
box which is a nice minimal image.

We also allow the default behaviour of sharing folder to VMs

By doing this we can stage our download files in a shared location
and speed up subsequent runs significantly.

Finally will create more verbose documentation.

Use correct google ns for dns upstream

Fix issue with check_certs playbook

check_certs task "Check_certs | Set 'sync_certs' to true" was failing
due to the dict not existing, this sets defaults that allows the
correct behavior of the conditionals.

fix flannel deployment, remove docker bridge before restarting

Remove need to pre-create writeable dir on CoreOS

Issue-229: Support Proxies in Docker Daemon

Update README.md