Do not support ruby 1.8.X on thinreport 0.8.0+
Do not support ruby 1.8.X on thinreport 0.8.0+

c.f. http://www.thinreports.org/news/2015/04/thinreports-0_8_0-released/

y-yagi/thinreports-rails,takeshinoda/thinreports-rails