oracle tests

[TomAugspurger]

Using the fact that op(RangeIndex, x) === op(Int64Index(RangeIndex, x)) to make a bunch of tests

this will fail on floordiv right now

AssertionError: Index are different

Index length are different
[left]:  5, RangeIndex(start=2, stop=-3, step=-1)
[right]: 10, Int64Index([2, 2, 1, 1, 0, 0, -1, -1, -2, -2], dtype='int64')
-

[jreback]

incorporated pandas-dev#11892

thanks!

I make floordiv just always return Int64Index, simpler that way :)