Fix docs (#497)

* Fix docs.

* Fix YAML.

* Prevent crashes with older pyyaml versions.

plugins/modules/acme_inspect.py

@@ -184,7 +184,7 @@ directory:
   description: The ACME directory's content
   returned: always
   type: dict
-  sample: |
+  sample:
     {
       "a85k3x9f91A4": "https://community.letsencrypt.org/t/adding-random-entries-to-the-directory/33417",
       "keyChange": "https://acme-v02.api.letsencrypt.org/acme/key-change",
@@ -204,7 +204,7 @@ headers:
   description: The request's HTTP headers (with lowercase keys)
   returned: always
   type: dict
-  sample: |
+  sample:
     {
       "boulder-requester": "12345",
       "cache-control": "max-age=0, no-cache, no-store",
@@ -215,7 +215,7 @@ headers:
       "cookies_string": "",
       "date": "Wed, 07 Nov 2018 12:34:56 GMT",
       "expires": "Wed, 07 Nov 2018 12:44:56 GMT",
-      "link": "<https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf>;rel=\"terms-of-service\"",
+      "link": '<https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf>;rel="terms-of-service"',
       "msg": "OK (904 bytes)",
       "pragma": "no-cache",
       "replay-nonce": "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGH",