Release connection correctly when no open transactions (#800)

Author: matthewmcgarvey

spec/avram/transaction_spec.cr

@@ -66,6 +66,11 @@ describe "Avram::SaveOperation" do
         operation.saved?.should be_true
       end
     end
+
+    it "releases connection after operation finishes and no transactions open", tags: Avram::SpecHelper::TRUNCATE do
+      PostTransactionSaveOperation.create!(title: "New Title", rollback_after_save: false)
+      TestDatabase.connections.should be_empty
+    end
   end
 
   describe "raising an error" do

src/avram/database.cr

@@ -221,8 +221,7 @@ abstract class Avram::Database
   rescue e : Avram::Rollback
     false
   ensure
-    # TODO: not sure of this
-    if current_connection._avram_in_transaction?
+    if !current_connection._avram_in_transaction?
       current_connection.release
       connections.delete(object_id)
     end