Fixing compiler errors and scheduler interface

daggy/include/daggy/DAG.hpp

@@ -7,6 +7,7 @@
 #include <unordered_set>
 #include <iterator>
 #include <functional>
+#include <optional>
 
 /*
    The DAG structure in daggy is just to ensure that tasks are run

daggy/include/daggy/Scheduler.hpp

@@ -18,13 +18,13 @@ namespace daggy {
                             , size_t maxParallelTasks
       );
       void runTasks(std::vector<Task> tasks
-                    , std::unordered_map<std::string, ParameterValue> parameters)
+                    , std::unordered_map<std::string, ParameterValue> parameters
                     , DAG dag = {} // Allows for loading of an existing DAG
       );
 
     private:
       std::unordered_map<std::string, std::shared_ptr<Executor>> executors_;
-      std::unordered_map<std::string, std::vector<std::future<TaskResult>>> jobs_;
+      std::unordered_map<std::string, std::vector<std::future<AttemptRecord>>> jobs_;
       std::unordered_map<std::string, ParameterValue> parameters_;
   };
 }

daggy/src/Scheduler.cpp

@@ -1,4 +1,4 @@
-#pragma once
+#include <daggy/Scheduler.hpp>
 
 namespace daggy {
   void Scheduler::registerExecutor(std::shared_ptr<Executor> executor, size_t maxParallelTasks) {