remove pr_head_sha input

The sha of latest commit in the PR is obtained from the github metadata

+ some small README adjustments

README.md

@@ -66,7 +66,6 @@ See [Testing Farm onboarding guide](https://docs.testing-farm.io/general/0.1/onb
 | `debug` | Print debug logs when working with testing farm | true |
 | `update_pull_request_status` | Action will update pull request status. | false |
 | `environment_settings` | Pass custom settings to the test environment. | empty |
-| `pr_head_sha` | SHA of the latest commit in PR. Used for setting commit statuses. | $(git rev-parse HEAD) |
 | `create_github_summary` | Create summary of the Testing Farm as GiHub Action job. Possible options: "false", "true", "key=value" | true |
 | `timeout` | Timeout for the Testing Farm job in minutes. | 480 |
 

action.yml

@@ -14,16 +14,16 @@ inputs:
     description: 'A testing farm API key'
     required: true
   git_url:
-    description: 'An url to the GIT repository'
+    description: 'An url to the GIT repository with TMT plans'
     required: true
   git_ref:
     description: 'A tmt tests branch which will be used for tests'
     required: false
     default: 'master'
   github_token:
-    description: GitHub TOKEN or PAT
+    description: 'GitHub TOKEN or PAT'
     required: false
-    default: ${{ github.token }}
+    default: '${{ github.token }}'
   tmt_plan_regex:
     required: false
     description: 'A tmt plan regex which will be used for selecting plans. By default all plans are selected.'
@@ -79,10 +79,6 @@ inputs:
     description: 'Pass specific settings, like post-install-script, to the testing environment.'
     required: false
     default: '{}'
-  pr_head_sha:
-    description: 'HEAD SHA of a Pull Request. Used for posting statuses to the PR. The value is obtained from `git rev-parse HEAD` if this input is not set.'
-    required: false
-    default: ''
   timeout:
     description: 'Action is waiting for testing farm to finish or until timeout is reached. Value is in minutes.'
     required: false

src/action.ts

@@ -37,10 +37,7 @@ async function action(pr: PullRequest): Promise<void> {
   const api = new TestingFarmAPI(tfInstance);
 
   // Get commit SHA value
-  let sha = getInput('pr_head_sha');
-  if (sha === '') {
-    sha = pr.sha;
-  }
+  const sha = pr.sha;
   debug(`SHA: '${sha}'`);
 
   // Set artifacts url