Add vector 2-norm test

[ubIQio]

Fails on high tolerance if result is >10?

[v923z]

@ubIQio I wouldn't get too hung up on the tolerance issue: some platforms have only floats. I would say, if you look at the results from numpy, and from ulab, and they are reasonably close, then I would accept them.

However, you have to update the expected file https://github.com/v923z/micropython-ulab/blob/master/tests/numpy/linalg.py.exp. The easiest way of doing that is to simply run the https://github.com/v923z/micropython-ulab/blob/master/build.sh script. That pulls in the latest micropython, compiles the firmware for unix, and runs the tests. At the end, if a test fails, or its expected file is not in ./tests/, then a new expected file will be generated in the root. You'll have to copy that to ./tests/numpy/ as mytest.py.exp. At that point, mytest.py.exp becomes the gold standard for mytest.py, and the results of mytest.py will in the future be compared against this file.

[v923z]

@ubIQio This looks good, many thanks for your efforts!