Add check mode and fixes boolean inputs (#111)

* Add check mode option

* Fixes boolean inputs

Boolean inputs weren't working properly before. Passing any value would
result in `true`, which is unexpected and not according to inputs
description. This change retrieves booleans with `getBooleanInput()` and
sets a default to `false`.

Relevant GitHub discussion and comment: https://github.com/actions/toolkit/issues/361#issuecomment-829507270

* Update action.yml

* Update test.yml

* Update test.yml

---------

Co-authored-by: Dawid Dziurla <dawidd0811@gmail.com>

main.js

@@ -15,8 +15,9 @@ async function main() {
         const vaultPassword = core.getInput("vault_password")
         const knownHosts = core.getInput("known_hosts")
         const options = core.getInput("options")
-        const sudo    = core.getInput("sudo")
-        const noColor = core.getInput("no_color")
+        const sudo    = core.getBooleanInput("sudo")
+        const noColor = core.getBooleanInput("no_color")
+        const checkMode = core.getBooleanInput("check_mode")
         const fileMode = 0600
 
         let cmd = ["ansible-playbook", playbook]
@@ -94,6 +95,10 @@ async function main() {
             process.env.ANSIBLE_FORCE_COLOR = "True"
         }
 
+        if (checkMode) {
+            cmd.push("--check")
+        }
+
         let output = ""
         await exec.exec(cmd.join(' '), null, {
           listeners: {