Replace torch. with autoray.numpy. operations
After this commit it still only works with torch and should indirectly perform the same torch operations as before. I put these changes in an separate commit so that if a regression was introduced in some commit later, it is easier to find the bug.
Replace some numerical operations so that VEGAS+ works with both torch and numpy
Add dtype arguments so that it is possible to integrate with float32 precision with numpy
A new VEGASMap._smooth_map method
A small docstring fix in VEGAS.integrate
More tests
Support other backends in vegas_test.py and use it to test with Numpy
Add special peak integrands to vegas_test.py to check that VEGAS+ works better than MonteCarlo for these integrands
Summary of changes:
Relevant issue: #14