Work with version specifiers.
Supported specifiers:
Install from PyPI:
python3 -m pip install --user dephell_specifier
from dephell_specifier import RangeSpecifier
'3.4' in RangeSpecifier('*')
# True
'3.4' in RangeSpecifier('<=2.7')
# False
'3.4' in RangeSpecifier('>2.7')
# True
'3.4' in RangeSpecifier('>2.7,<=3.4')
# True
'3.4' in RangeSpecifier('<2.7 || >=3.4')
# True