Update rr to ~> 1.0
Update rr to ~> 1.0

Fixes:  undefined local variable or method `instance_methods'
for #<RR::DoubleDefinitions::DoubleDefinition:0x007fcc6b1bee98>

when running specs

xiaohui-zhangxh/treetop,maddenp/treetop,nathansobo/treetop,cjheath/treetop