Fixed library json file so platformio can build again

library.json

@@ -16,5 +16,17 @@
     ],
     "license": "None Yet",
     "frameworks": "*",
-    "platforms": "*"
+    "platforms": "*",
+    "build": {
+        "srcDir": "src",
+        "flags": [
+            "-std=c++17",
+            "-I src/Vector3D",
+            "-I src/Matrix",
+            "-I src/Quaternion"
+        ],
+        "srcFilter": [
+            "-<*/unit-tests/>"
+        ]
+    }
 }