Equality and inequality signs as operators in SASS

При `shiftRight(2)` ломается вот этот тест:

```
  1) sass/condition >> 1.p:

Expected:
['condition',
  ['atkeyword',
    ['ident', 'else']],
  ['s', ' '],
  ['ident', 'if'],
  ['s', ' '],
  ['variable',
    ['ident', 'ocean']],
  ['s', ' '],
  ['operator', '=='],
  ['s', ' '],
  ['string', ''big'']]

Result:
['condition',
  ['atkeyword',
    ['ident', 'else']],
  ['s', ' '],
  ['ident', 'if'],
  ['s', ' '],
  ['variable',
    ['ident', 'ocean']],
  ['s', ' '],
  ['operator', '=='],
  ['string', ''big'']]
```