TST: fix dos test for 32 bit Anaconda

Merged username-removed-261087 requested to merge tdaff/ase:dos32bit into master

See: https://ci.appveyor.com/project/tdaff/ase/build/job/u6yxt7e0ifkq44k2

The cumulation of errors in the different dos caluculation methods using 32-bit python (probably in numpy) goes slightly over the current test precision (it's about 1.06e-14):

assert abs(dos1 - dos1w).max() < 1e-14

Increase the tolerence slightly to allow the tests to pass.

Edited by username-removed-261087