Squashed commit of the following:

commit d85bf10eeb533886873d471409cc227640c2b0bd
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 23:40:15 2013 +0100

    (wip) trying to discover what fail

commit b502b0a2ae85f21a6cada9dda31e79b442070518
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 23:35:34 2013 +0100

    (wip) trying to discover what fail

commit 5c43739ba1e5e639b6b28d2c526b38dc34d199e1
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 22:48:54 2013 +0100

    (wip) trying to discover what fail

commit 4e193feab68828cbc397753872200110b7d23909
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 22:43:17 2013 +0100

    (wip) trying to discover what fail

commit 5e0c1c62ba3edefefdf4fe61f7a5cc431cc31cc2
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 22:39:57 2013 +0100

    (wip) trying to discover what fail

commit 97290e61ba0842af85066052d310232057b4e8eb
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 22:37:07 2013 +0100

    (wip) trying to discover what fail

commit f91861262fff09d6fd4c943e0977649d496ff26b
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 22:30:29 2013 +0100

    (wip) trying to discover what fail

commit 7ef258b7f2844b01a05e75637f40bdee90e46251
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 22:17:18 2013 +0100

    Add --trace option to rake travis call

commit 0fb01b8df09bef98c6e1912062fa17a25f54cdb5
Author: Cédric Néhémie <cedric.nehemie@gmail.com>
Date:   Sun Mar 17 22:09:55 2013 +0100

    Remove use of bundle exec
Refactor model helper to have better spec descriptions