change dependency of angular to 1.2.1 or above

1.2.1 is the minimum version that elif works with. Instead of requiring 1.2.16 exactly, allow bower to pick any version 1.2.1 or later. Also bower needs a tag on the commit to discover which version to use. See [Updating And Maintenance](http://bob.yexley.net/creating-and-maintaining-your-own-bower-package/#updatingandmaintenance)

Thank you!