v0.5.0.

Bg Fix: check value range limit when adding an element.
Changed some name for properties.
Removed options object in favour of range argument.
Added new Docker for travis..

On branch master
modified:   .travis.yml
modified:   Readme.md
modified:   lib/toni.js
modified:   package.json
new file:   test/add-del-out-of-range-test.js
modified:   test/add-del-stress-test.js