Added missing test

sample/test_cosmopower.cpp

@@ -0,0 +1,29 @@
+#include <cmath>
+#include <iostream>
+#include "cosmopower.hpp"
+
+using namespace std;
+using namespace CosmoTool;
+
+int main()
+{
+   CosmoPower cp;
+   CosmoPower::CosmoFunction f[] = { CosmoPower::POWER_EFSTATHIOU, CosmoPower::HU_WIGGLES, CosmoPower::HU_BARYON, CosmoPower::POWER_SUGIYAMA };
+   int num_F = sizeof(f)/sizeof(f[0]);
+
+   cp.setFunction(f[0]);
+   cp.normalize();
+   for (int ik = 0; ik < 100; ik++)
+    {
+      double k = pow(10.0, 4*ik/100.-3);
+      
+      cout << k << " ";
+      for (int q = 0; q < num_F; q++)
+        {
+          cp.setFunction(f[q]);
+          cout << cp.power(k) << " ";
+        } 
+      cout << endl;
+    }
+   return 0;
+}