Adding BigInt, BigRat, NullBigInt, NullBigRat

To assist with unmarshaling Oracle numeric types (since they are
arbitrary precision).

Signed-off-by: Manolo Gutierrez <m.gutierrez@modcloth.com>
Trivial change to make CI/Dan happy.
Merge remote-tracking branch 'origin/master' into 50192387-adding-sql-support-for-arbitrary-precision
Merge pull request #1 from modcloth/50192387-adding-sql-support-for-arbitrary-precision

Adding BigInt, BigRat, NullBigInt, NullBigRat