test(tests/meshIO): added basic test suite for meshIO

just tests the constuctor, getMesh, and isLoaded method. This confirms that a basic spherical mesh can be loaded in correctly

tests/meshIO/meshIOTest.cpp

@@ -0,0 +1,26 @@
+#include <gtest/gtest.h>
+#include "meshIO.h"
+#include <iostream>
+#include <string>
+#include "mfem.hpp"
+
+std::string EXAMPLE_FILENAME = std::string(getenv("MESON_SOURCE_ROOT")) + "/src/resources/mesh/sphere.msh";
+
+
+class meshIOTest : public ::testing::Test {};
+
+TEST_F(meshIOTest, DefaultConstructor) {
+    EXPECT_NO_THROW(MeshIO meshIO(EXAMPLE_FILENAME));
+}
+
+TEST_F(meshIOTest, IsLoaded) {
+    MeshIO meshIO(EXAMPLE_FILENAME);
+    EXPECT_EQ(meshIO.IsLoaded(), true);
+}
+
+TEST_F(meshIOTest, GetMesh) {
+    MeshIO meshIO(EXAMPLE_FILENAME);
+    mfem::Mesh& mesh = meshIO.GetMesh();
+    EXPECT_EQ(mesh.GetNE(), 670);
+    EXPECT_EQ(mesh.GetNV(), 201);
+}