Allocate more space for laplacian in spline test.

The laplacian is stored as x, y, and z components during the spline evaluation and
summed into the x component at the end.    Need to allocate more space for it in the unit test.

Fixes QMCPACK#941

src/spline2/tests/gen_bspline_values.py

@@ -290,7 +290,7 @@ def evaluate_spline_3D():
 
   print
   print
-  print '  Array<T, 1> lap(1);'
+  print '  Array<T, 2> lap(1,3);'
   print '  bs.evaluate_vgl(pos, v, dv, lap);'
 
   lap = diff(e,xs,2) + diff(e,ys,2) + diff(e,zs,2)

src/spline2/tests/test_multi_spline.cpp

@@ -228,7 +228,7 @@ void test_splines()
   REQUIRE(hess(0, 5) == Approx(    34.53786329));
 
 
-  Array<T, 1> lap(1);
+  Array<T, 2> lap(1,3);
   bs.evaluate_vgl(pos, v, dv, lap);
   // Value
   REQUIRE(v(0) == Approx(  -0.9476393279));