gemspec / Gemfile: Relax rake dependency to satisfy rake v10 and v12
As of 2017/10/04, Debian ships rake v12 in unstable, and rake v10 in stretch. To ease backporting, this commits enable the use of both rake versions.
Closes #263 (closed)
As of 2017/10/04, Debian ships rake v12 in unstable, and rake v10 in stretch. To ease backporting, this commits enable the use of both rake versions.
Closes #263 (closed)