update gemspec to v1.1.0

simplekit.gemspec

 # -*- ruby -*-
-_VERSION = "1.0.0"
+_VERSION = "1.1.0"
 
 Gem::Specification.new do |s|
   s.name = "simplekit"
   s.version = _VERSION
-  s.date = "2018-07-12"
+  s.date = "2020-04-09"
   s.summary = "Discrete event simulation engine."
   s.homepage = "https://gitlab.nps.edu/pjsanche/simplekit-ruby.git"
   s.email = "pjs@alum.mit.edu"