Split tests to cpu and cuda

test/cuda/layers/test_input.cu

@@ -0,0 +1,19 @@
+#include <cuda_runtime_api.h>
+#include <gtest/gtest.h>
+
+#include "input.cuh"
+
+TEST(InputLayerTest, InputForward) {
+    std::vector<float> input = {0.573f, 0.619f, 0.732f, 0.055f, 0.243f, 0.316f};
+    CUDANet::Layers::Input inputLayer(6);
+    float*                 d_output = inputLayer.forward(input.data());
+
+    std::vector<float> output(6);
+    cudaError_t        cudaStatus = cudaMemcpy(
+        output.data(), d_output, sizeof(float) * 6, cudaMemcpyDeviceToHost
+    );
+    EXPECT_EQ(cudaStatus, cudaSuccess);
+    EXPECT_EQ(input, output);
+
+    
+}