Add example Ansible playbook to create config file

Add Jinja2 template for Kubeadm configuration file. Add Ansible playbook to create a configuration file from the Jinja2 template. Add README.md with instructions and more information.

Signed-off-by: Scott Lowe <scott.lowe@scottlowe.org>

ansible/kubeadm-template/README.md

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+# Using Ansible to Template a Kubeadm Configuration File
+
+These files provide an example of how to use Ansible's `template` module to create a Kubeadm configuration file from a Jinja2 template. The template and Ansible playbook were tested using Ansible 2.5 on Fedora 27, but should work on any recent version of Ansible on any supported platform.
+
+**NOTE:** At this time, the `kubeadm.conf` generated by this playbook has _not_ been verified to create a working, conformant Kubernetes cluster. It is for demonstration purposes only.
+
+## Contents
+
+* **kubeadm.conf.j2**: This Jinja2 template contains the framework for a Kubeadm configuration file.
+
+* **README.md**: The file you're currently reading.
+
+* **template.yml**: This Ansible playbook takes a series of variables along with the `kubeadm.conf.j2` Jinja2 template and generates a Kubeadm configuration file.
+
+## Instructions
+
+These instructions assume that you have Ansible installed and functioning correctly on your system.
+
+1. Place the files from the `ansible/kubeadm-template` directory of this GitHub repository into a directory on your local system. You can clone the entire "learning-tools" repository (using `git clone`) or just download the specific files from the `ansible/kubeadm-template` folder.
+
+2. (Optional) Edit `template.yml` to specify different values for the variables defined in the playbook.
+
+3. Run `ansible-playbook -i "localhost," -c local template.yml` to generate a Kubeadm configuration file from the template. The generated file will reside in the same directory as `kubeadm.conf`.
+
+Enjoy!
+
+## License
+
+This content is licensed under the MIT License.

ansible/kubeadm-template/kubeadm.conf.j2

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+apiVersion: kubeadm.k8s.io/v1alpha1
+  kind: MasterConfiguration
+  api:
+    advertiseAddress: {{ apiAdvertiseAddress }}
+  etcd:
+    endpoints:
+    - {{ etcdServer1 }}
+    - {{ etcdServer2 }}
+    - {{ etcdServer3 }}
+  networking:
+    podSubnet: {{ podSubnet }}
+    serviceSubnet: {{ serviceSubnet }}
+  kubernetesVersion: {{ k8sVersion }}
+  cloudProvider: {{ cloudProvider }}
+  token: {{ kubeadmToken }}
+  tokenTTL: "0"
+  apiServerCertSANs: [{{ apiServerCertSANs }}]
+  featureGates:
+    CoreDNS: true
+    DynamicKubeletConfig: true
+  apiServerExtraArgs:
+    endpoint-reconciler-type: lease
+    admission-control: NamespaceAutoProvision,Initializers,NamespaceLifecycle,LimitRanger,ServiceAccount,PersistentVolumeLabel,DefaultStorageClass,DefaultTolerationSeconds,NodeRestriction,ResourceQuota,PodTolerationRestriction
+    cloud-provider: {{ cloudProvider }}
+    audit-log-path: "/var/log/kube-audit"
+    audit-log-maxage: "10"
+    audit-log-maxsize: "100"
+    audit-policy-file: "/etc/kubernetes/audit/audit-policy.yaml"
+  controllerManagerExtraArgs:
+    cloud-provider: {{ cloudProvider }}
+    configure-cloud-routes: "false"
+  apiServerExtraVolumes: 
+    - name: "audit-policy"
+      hostPath: "/etc/kubernetes/audit"
+      mountPath: "/etc/kubernetes/audit"

ansible/kubeadm-template/template.yml

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+---
+- hosts: all
+  vars:
+    apiAdvertiseAddress: 192.168.100.100
+    etcdServer1: 192.168.100.200
+    etcdServer2: 192.168.100.201
+    etcdServer3: 192.168.100.202
+    podSubnet: 172.24.0.0/16
+    serviceSubnet: 10.0.0.0/16
+    k8sVersion: 1.9.6
+    cloudProvider: aws
+    kubeadmToken: 8fcc26.83ab1665d9142018
+    apiServerCertSANs: apiserver.cluster.io
+
+  tasks:
+    - name: Render kubeadm.conf template
+      local_action:
+        module: template
+        src: kubeadm.conf.j2
+        dest: kubeadm.conf