re-implement asceding? and friends with doc
fix sort_spec.rb

Since the original ascending? is split into two functions:  ascending?
and non_descending? which have different meanings.

```ruby
    sample = [31, 37, 26, 30, 2, 30, 1, 33, 5, 14, 11, 13, 17, 35, 4]
```

The sample in the spec is has duplicate elements, therefor it is not
ascending (monotonically increasing order) but non-descending
(monotonically non-decreasing order).  So I had to change
“Functional.ascending?(sorted)” to  “Functional.non_descending?(sorted)”
change and add spec for ascending? and friends
travis ci add ruby 2.1.1 and rbi 2.2.2
add rbx-2.2.6 to travis ci
remove rbx-19mode from .travis.yml

Note that the syntax of rbx-19mode isn't supported anymore
<http://docs.travis-ci.com/user/languages/ruby/>
Revert "remove rbx-19mode from .travis.yml"

This reverts commit ad7628d230bdb0285b05594a6bacff350ac6be27.
remove rbx-19mode from .travis.yml

rbx-19mode is not supported.
http://rubies.travis-ci.org/rubinius
Updated Travis config
t push origin masterMerge branch '404pnf-simplify'