ListGroup component
Merge pull request #168 from brainary/list-group

Adding ListGroup component
Fix travis build

Seems a recent change to travis.ci relies on version numbers being
strings, otherwise they are interpreted numbers which in this case was
dropping the trailing "0".
fix a typo where the file name was different from the one in docs/src/ComponentsPage.js
Merge pull request #177 from dozoisch/doc_filename_typo

Typo in DropdownButtonSizes file name
Check mountable prop is truthly

This additional check is necessary since `typeof null === 'object'`,
react@0.11 it will evaluate prop types before setting their value in some
cases.

closes #180 #175
Correct docs to suggest use of `ModalTrigger` for `Modal`s
Merge pull request #181 from pieterv/mountable-proptype-fix

Mountable propType fix
Added input type="submit" support, and ability to override component
class for Buttons