fix: added tests and improved code

actions/testdata/env.workflow

@@ -1,9 +1,17 @@
 workflow "test" {
   on = "push"
-  resolves = ["test-action"]
+  resolves = [
+    "test-action-repo",
+    "test-action-ref",
+  ]
 }
 
-action "test-action" {
+action "test-action-repo" {
   uses = "docker://alpine:3.9"
   runs = ["sh", "-c", "echo $GITHUB_REPOSITORY | grep '^nektos/act$'"]
-}
+}
+
+action "test-action-ref" {
+  uses = "docker://alpine:3.9"
+  runs = ["sh", "-c", "echo $GITHUB_REF | grep '^refs/'"]
+}