Fixed some cmake errors

CMakeLists.txt

@@ -2,46 +2,8 @@ cmake_minimum_required(VERSION 3.6)
 project(Vector3D)
 
 add_subdirectory(unit-tests)
+add_subdirectory(src)
 
 set(CMAKE_CXX_STANDARD 11)
 
 add_compile_options(-fdiagnostics-color=always)
-
-# Vector 3D Interface
-add_library(vector-3d-intf
-    INTERFACE
-)
-
-target_include_directories(vector-3d-intf
-    INTERFACE
-    .
-)
-
-# Matrix
-add_library(matrix 
-    STATIC
-    Matrix.cpp
-)
-
-target_link_libraries(matrix
-    PUBLIC
-    vector-3d-intf
-    PRIVATE
-)
-
-set_target_properties(matrix
-    PROPERTIES
-    LINKER_LANGUAGE CXX
-)
-
-# Vector3d
-add_library(vector-3d 
-    STATIC
-    Vector3D.cpp
-)
-
-target_link_libraries(vector-3d
-    PUBLIC
-    vector-3d-intf
-    PRIVATE
-)