Prevent dtype conversion in Aesara during testing to avoid a bug

This change avoids the bug fixed in
pymc-devs/pytensor#348.

Author: brandonwillard

pymc3/tests/test_transforms.py

@@ -307,7 +307,7 @@ def check_vectortransform_elementwise_logp(self, model, vect_opt=0):
         assert logpt(x).ndim == jacob_det.ndim
 
         # Hack to get relative tolerance
-        a = logpt(x, array, jacobian=False).eval()
+        a = logpt(x, array.astype(aesara.config.floatX), jacobian=False).eval()
         b = logp_nojac.eval()
         close_to(a, b, np.abs(0.5 * (a + b) * tol))