Update gemspec

Author: gauravkukade

jekyll-text-theme.gemspec

@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency "jekyll-sitemap", "~> 1.0"
   spec.add_runtime_dependency "jekyll-feed", "~> 0.1"
   spec.add_runtime_dependency "jemoji", "~> 0.8"
+  spec.add_development_dependency "rake", "~> 10.0"
 
   spec.add_development_dependency "bundler"
-  spec.add_development_dependency "rake", "~> 10.0"
 end