add rails 5.0 5.1 5.2 to ci builds (#98)
add rails 5.0 5.1 5.2 to ci builds (#98)

* add rails 5.0 5.1 5.2 to ci builds

* reduce build matrix to 1 ruby and 2 rails versions #98

* restore ci test against rails 5.0 and 5.1, and fix the version passed in to ~>

venuu/jsonapi-authorization,venuu/jsonapi-authorization