now able to pass a function to the directive and it's reachable in the template

primarily for ng-click
tweaked one of the directive tests for template-function

to be more clear how a passed function should be called in angular
ensure that npm has dependencies installed globally
apparently global karma install is not a good idea
explicitly list firefox/chrome karma launchers as dev dependencies

launchers aren't being installed implicitly on travis (though they are locally)
guess and check adding jasmin as explicit devDependency
test config was expecting jquery to come from bower, but set it up to come from npm
Merge pull request #3 from robdennis/feature/allow_passed_functions

Feature/allow passed functions