feat: github-api-url (#88)

closes #77

---------

Co-authored-by: Parker Brown <17183625+parkerbxyz@users.noreply.github.com>

tests/snapshots/index.js.md

@@ -16,6 +16,22 @@ Generated by [AVA](https://avajs.dev).
     private_key — 'private_key' is deprecated and will be removed in a future version. Use 'private-key' instead.␊
     skip_token_revoke — 'skip_token_revoke' is deprecated and will be removed in a future version. Use 'skip-token-revoke' instead.`
 
+## main-custom-github-api-url.test.js
+
+> stderr
+
+    ''
+
+> stdout
+
+    `owner and repositories set, creating token for repositories "actions/create-github-app-token" owned by "actions"␊
+    ::add-mask::ghs_16C7e42F292c6912E7710c838347Ae178B4a␊
+    ␊
+    ::set-output name=token::ghs_16C7e42F292c6912E7710c838347Ae178B4a␊
+    ::save-state name=token::ghs_16C7e42F292c6912E7710c838347Ae178B4a␊
+    ␊
+    ::set-output name=expiresAt::2016-07-11T22:14:10Z`
+
 ## main-missing-app-id.test.js
 
 > stderr