Update tasks/main.yml to remove unnecessary "templates/" and corrected the version number for redhat in repo.j2.

Since the templates are already in a templates directory ansible knows to look there so calling src=templates/repo.j2 caused an error as ansible looked in /etc/ansible/roles/plight/templates/templates/repo.j2

In the repo.j2 file the version numbers for redhat did not match the links on the copr server.