Allow some validation predicates to accept any number
Add between() validation predicate
Merge pull request #160 from devinus/validation-predicates

Allow some validation predicates to accept any number
Add Decimal support

Update postgrex to 0.4.0
Distinct: add basic distinct to the query DSL (+ add to PG adapter)
Distinct: refactor group_by/distinct into BuilderUtil
Distinct: factor out common code for distinct/group_by in normalizer
Distinct: rework validator to ensure group_by leftmost express match the distinct expr
Distinct: validate distinct on order_by not on group_by
Distinct: rename escape_expr in escape_fields_and_var + Enum.first => List.first
Distinct: proposal for the documentation of 'distinct'
Distinct: add a 's' to the function name, to be consistent
Distinct: add a test for distinct without order_by
Distinct: add some metadata to the error raised by the validator