CircleCI Added to module

This is release is mostly to denote that CircleCI was added to help us release more stable versions, and that this version itself is stable.

Fixes Syntax errors in v2.0.0

Fix expected expression but found "[" (#12)

* fix expected expression but found "["

* security_groups need to be a list.

* Remove extra var

* Fix wrong explanation

v2.1.0

Allow people to override user_data and name_prefix. (#9)

* Allow people to override user_data and name_prefix.

* Forgot to add the data file.

* Address PR comments. Update the README accordingly.

* Typo.

* Formatting.

v2.0.0: Allow each instance to have a public IP assigned via LC. (#5)

This adds the ability to pass associate_public_ip_address as a parameter. This is being released as a major release as it changes the behavior of this module. It no longer inherits the default from the VPC.