A sqlite DB is detected as not a binary

[pombredanne]

This file https://github.com/linq2db/linq2db/raw/5e26fa1693208b92b0791dff445ab7b42e79fb1b/Data/Northwind.sqlite is not detected correctly as binary

>>> is_binary('Northwind.sqlite')
DEBUG:binaryornot.helpers:nontext_ratio1: 0.9697265625
DEBUG:binaryornot.helpers:nontext_ratio2: 0.98828125
DEBUG:binaryornot.helpers:is_likely_binary: True
DEBUG:binaryornot.helpers:detected_encoding: {'confidence': 0.9377949365075317, 'language': 'Bulgarian', 'encoding': 'windows-1251'}
DEBUG:binaryornot.helpers:success: decodable_as_unicode: True
DEBUG:binaryornot.helpers:failure: decodable_as_unicode: True
False

IMHO it should be a binary

[pombredanne]

In this case I would thing this would be sensible:

    if nontext_ratio1 > 0.90 and nontext_ratio2 > 0.90:
        return True

[pombredanne]

attached is a test file which is a truncated sqlite db reported as not a binary
test.sqlite.zip

[pombredanne]

@pydanny Thank you ++ do you mind to tag the current master? and/or even better: make a new Pypi release?