feat: spinup preview environment on open/reopen (#86)

Author: Alanoll

lib/pull_preview/github_sync.rb

@@ -196,7 +196,7 @@ def guess_action_from_event
         return :pr_down
       end
 
-      if pr_labeled? && pr_has_label?
+      if (pr_opened? || pr_reopened? || pr_labeled?) && pr_has_label?
         return :pr_up
       end
 
@@ -370,6 +370,16 @@ def pr_synchronize?
         github_context["action"] == "synchronize"
     end
 
+    def pr_opened?
+      pull_request? &&
+        github_context["action"] == "opened"
+    end
+
+    def pr_reopened?
+      pull_request? &&
+        github_context["action"] == "reopened"
+    end
+
     def pr_closed?
       pull_request? &&
         github_context["action"] == "closed"