Prevent calling .norm() on integer matrices in the unit tests.
(transplanted from 333d23bc4a463f047bfde524ba92cc49397974b6)

--HG--
branch : 3.1
extra : transplant_source : 3%3D%23%BCJF%3F%04%7B%FD%E5%24%BA%92%CCI9yt%B6
bump to 3.1.3

--HG--
branch : 3.1
Added tag 3.1.3 for changeset 2249f9c22fe8

--HG--
branch : 3.1
fix a typo in commit 4b483eaddf74 (regarding MKL on windows)
(transplanted from 62ed8708b7e6711a52e9735fa7177dc91773dc2d)

--HG--
branch : 3.1
extra : transplant_source : b%ED%87%08%B7%E6q%1AR%E9s_%A7%17%7D%C9%17s%DC-