fix(tests): compile errors on 2018.4.26f1 (#38)

Author: amirebrahimi

Tests/Editor/MeshUtilsTest.cs

@@ -412,7 +412,11 @@ public void ShouldGetMeshUVs()
             mesh.vertices = new Vector3[4];
             for (int i = 0; i < uvs.Length; i++)
             {
+#if UNITY_2018
+                mesh.SetUVs(i, uvs[i].ToList());
+#else
                 mesh.SetUVs(i, uvs[i]);
+#endif
             }
 
             var allUVs = MeshUtils.GetMeshUVs(mesh);

Tests/Editor/Whinarn.UnityMeshSimplifier.Editor.Tests.asmdef

@@ -1,7 +1,10 @@
 {
     "name": "Whinarn.UnityMeshSimplifier.Editor.Tests",
     "references": [
-        "GUID:77ccaf49895b0d64e87cd4b4faf83c49"
+            "Whinarn.UnityMeshSimplifier.Runtime"
+    ],
+    "optionalUnityReferences": [
+        "TestAssemblies"
     ],
     "includePlatforms": [
         "Editor"
@@ -11,7 +14,5 @@
     "overrideReferences": false,
     "precompiledReferences": [],
     "autoReferenced": true,
-    "defineConstraints": [],
-    "versionDefines": [],
-    "noEngineReferences": false
+    "defineConstraints": []
 }