Address linter complaints.

* Truthy values should be true or false rather than yes or no
* Linter won't allow hard-coded 'latest' package state

defaults/main.yml

@@ -27,7 +27,7 @@ certbot_create_standalone_stop_services:
   # - apache
   # - varnish
 
-certbot_install_from_pypi: no
+certbot_install_from_pypi: false
 certbot_pypi_version: latest
 
 # To install from source (on older OSes or if you need a specific or newer

tasks/install-from-pypi.yml

@@ -4,7 +4,7 @@
     - certbot_pypi_version == "latest"
   pip:
     name: "{{ item }}"
-    state: latest
+    state: "{{ certbot_pypi_version }}"
   with_items:
     - certbot
     - certbot-nginx