Add speedtest cli to Telegraf config

- Install speedtest CLI on cluster leader
- Install speedtest telegraf config on leader
- cleanup hosts in ping list
- Add custom shell script on leader to output speedtest data to influxdb
- improve version checking of Telegraf binary
- bump telegraf version
- allow ' package-latest' to pass ansible-lint

.ansible-lint.yml

@@ -14,6 +14,7 @@ skip_list:
   - meta-incorrect
   - role-name
   - ignore-errors
+  - package-latest
 
 warn_list:
   - experimental