* Add logic to filter out warning IDs via environment variable
Usage: SPACY_WARNING_EXCLUDE=W001,W007
* Add warnings for empty vectors
* Add warning if no word vectors are used in .similarity methods
For example, if only tensors are available in small models – should hopefully clear up some confusion around this
* Capture warnings in tests
* Rename SPACY_WARNING_EXCLUDE to SPACY_WARNING_IGNORE