Delete dev deps from gemspec, as they are already listed in Gemfile

Author: markets

middleman-syntax.gemspec

@@ -12,12 +12,6 @@ Gem::Specification.new do |s|
   s.license = "MIT"
   s.files = `git ls-files -z`.split("\0")
   s.test_files = `git ls-files -z -- {fixtures,features}/*`.split("\0")
-  s.require_paths = ["lib"]
   s.add_runtime_dependency("middleman-core", [">= 3.2"])
   s.add_runtime_dependency("rouge", ["~> 3.2"])
-  s.add_development_dependency("aruba")
-  s.add_development_dependency("cucumber")
-  s.add_development_dependency("haml")
-  s.add_development_dependency("kramdown")
-  s.add_development_dependency("slim")
 end