add first header file

Makefile

@@ -8,7 +8,7 @@ BUILD_DIR=$(REPO_DIR)/build
 CXX=g++
 CXX_FLAGS=-g -std=c++14 \
           -I/usr/local/include \
-          -I$(INCLUDE_DIR)/include \
+          -I$(INCLUDE_DIR) \
           -I$(SUBMOD_DIR)/json/single_include
 LD_FLAGS=-L/usr/local/lib \
          -lexchange_server
@@ -19,10 +19,10 @@ XSTEST_OBJS=$(subst $(REPO_DIR),$(BUILD_DIR),$(XSTEST_SRCS:.cc=.o))
 
 all: $(BUILD_DIR)/xs-test
 
-$(BUILD_DIR)/xs-test: $(XSTEST_OBJS) $(XSTEST_HDRS)
+$(BUILD_DIR)/xs-test: $(XSTEST_OBJS)
 	$(CXX) -o $@ $(LD_FLAGS) $(XSTEST_OBJS)
 
-$(BUILD_DIR)/%.o: $(REPO_DIR)/%.cc
+$(BUILD_DIR)/%.o: $(REPO_DIR)/%.cc $(XSTEST_HDRS)
 	mkdir -p $(dir $@)
 	$(CXX) -o $@ -c $(CXX_FLAGS) $<
 

include/Config.h

+#ifndef XS_TEST_CONFIG_H_INCLUDED
+#define XS_TEST_CONFIG_H_INCLUDED
+
+#include "nlohmann/json.hpp"
+
+#include <memory>
+
+
+namespace xs { namespace test
+{
+    class Config final
+    {
+    public:
+        static std::unique_ptr<Config> parse(const std::string& text) noexcept;        
+
+    private:
+    };
+} }
+
+#endif

src/xs-test.cc

 #include <iostream>
 
-// #include "Config.hpp"
+#include "Config.h"
 #include "nlohmann/json.hpp"