Rename link 'template' data attribute

[gdlx]

Here is a fix for issue #80.

Link's template data attribute is already used by Twitter Bootstrap's tooltip JS, producing strange behavior when using both BS Tooltip and Cocoon on the same link.

This fix renames template to association-insertion-template to limit collision risk.

Since this attribute is generated by the gem itself, there should not be any regression, except if some user does JS customization of template, which is contradictory with the purpose of the gem.

Specs are updated with the new attribute name (I had to change data attributes order since Rails seems to sort them). All 30 specs successful.

I did not update the readme since there was no mention of template but maybe you will want to add a note about the change.

Thanks !

[nathanvda]

Nice one. Indeed the template name is obviously a bit too generic. Thanks.

[gdlx]

Indeed the template name is obviously a bit too generic

Sure...but it's also true for Bootstrap...

I should send them an issue about that too, but as i'm using bootstrap-sass and not the root version, I don't feel comfortable sending a pull request.