Add HashiCorp Nomad provider (#483)

* provider: adding Nomad provider

* updating CONTRIBUTING.md with Nomad provider

* updated README.md by adding the Nomad provider

* fix typo

* adding nomad/api and nomad/testutil deps

* adding Nomad binary dependency for provider tests

* fixed the nomad binary download command step and added tolerations to the nomad provider.

* adding nomad provider demo gif

* adding my name to authors

* adding two missing go-rootcerts files after dep ensure

* delete pod comment

vendor/github.com/hashicorp/vault/website/LICENSE.md

@@ -0,0 +1,10 @@
+# Proprietary License
+
+This license is temporary while a more official one is drafted. However,
+this should make it clear:
+
+The text contents of this website are MPL 2.0 licensed.
+
+The design contents of this website are proprietary and may not be reproduced
+or reused in any way other than to run the website locally. The license for
+the design is owned solely by HashiCorp, Inc.

vendor/github.com/hashicorp/vault/website/source/api/system/license.html.md

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+---
+layout: "api"
+page_title: "/sys/license - HTTP API"
+sidebar_title: "<code>/sys/license</code>"
+sidebar_current: "api-http-system-license"
+description: |-
+  The `/sys/license` endpoint is used to view and update the license used in 
+  Vault.
+---
+
+# `/sys/license`
+
+~> **Enterprise Only** – These endpoints require Vault Enterprise.
+
+The `/sys/license` endpoint is used to view and update the license used in 
+Vault.
+
+## Read License
+
+This endpoint returns information about the currently installed license.
+
+| Method   | Path                         | Produces               |
+| :------- | :--------------------------- | :--------------------- |
+| `GET`    | `/sys/license`                | `200 application/json` |
+
+### Sample Request
+
+```
+$ curl \
+    --header "X-Vault-Token: ..." \
+    http://127.0.0.1:8200/v1/sys/license
+```
+
+### Sample Response
+
+```json
+{
+  "data": {
+    "expiration_time": "2017-11-14T16:34:36.546753-05:00",
+    "features": [
+      "UI",
+      "HSM",
+      "Performance Replication",
+      "DR Replication"
+    ],
+    "license_id": "temporary",
+    "start_time": "2017-11-14T16:04:36.546753-05:00"
+  },
+  "warnings": [
+    "time left on license is 29m33s"
+  ]
+}
+```
+
+## Install License
+
+This endpoint is used to install a license into Vault.
+
+| Method   | Path                         | Produces               |
+| :------- | :--------------------------- | :--------------------- |
+| `PUT`    | `/sys/license`                | `204 (empty body)` |
+
+### Parameters
+
+- `text` `(string: <required>)` – The text of the license.
+
+*DR Secondary Specific Parameters*
+
+  - `dr_operation_token` `(string: <required>)` - DR operation token used to authorize this request.
+
+
+### Sample Payload
+
+```json
+{
+  "text": "01ABCDEFG..."
+}
+```
+
+### Sample Request
+
+```
+$ curl \
+    --header "X-Vault-Token: ..." \
+    --request PUT \
+    --data @payload.json \
+    http://127.0.0.1:8200/v1/sys/license
+```