Improve testing code step 1 (facebookresearch#3451)

Summary:
Pull Request resolved: facebookresearch#3451

This is a first step to clean up the faiss codebase following T187322081

Reviewed By: junjieqi

Differential Revision: D57448335

fbshipit-source-id: c9760d01479d3352b786bbcf2015251e7a7168d6

Author: Xiao Fu

tests/test_index_binary.py

@@ -142,7 +142,6 @@ def test_range_search(self):
                 self.assertTrue(set(range_res) <= set(I[i]))
                 nt2 += 1
             # in case of equality we have a problem with ties
-        print('nb tests', nt1, nt2)
         # nb tests is actually low...
         self.assertTrue(nt1 > 19 and nt2 > 19)
 
@@ -287,8 +286,6 @@ def test_ivf_nprobe(self):
         ref_index.add(xb)
         ref_D, ref_I = ref_index.search(xq, k)
 
-        print(D[0], ref_D[0])
-        print(I[0], ref_I[0])
         assert np.all(D == ref_D)
         # assert np.all(I == ref_I)  # id may be different