Suggestion: Rename test.py to avoid shadowing trap

[SaschaHornauer]

Python has a test package which can shadow the import of the test.py module, leading to an ImportError when importing NN or kNN.

https://docs.python.org/2.7/library/test.html?highlight=test#module-test https://docs.python.org/3.5/library/test.html

I suggest to rename it to test_embedding.py or something like that.