fix(bootstrap-sass): Bump bootstrap-sass gem to 3.4.0 (#1159)

* Bump bootstrap-sass gem to 3.4.0

Resolves XSS vulnerability

* build(bootstrap-sass gem): Update bootstrap-sass gem to 3.4.0 resolve XSS vulnerability

Author: daslicious

patternfly-sass.gemspec

@@ -12,7 +12,7 @@ Gem::Specification.new do |s|
   s.license  = 'Apache-2.0'
 
   s.add_runtime_dependency 'sass', '~> 3.4.15'
-  s.add_runtime_dependency 'bootstrap-sass', '~> 3.3.7'
+  s.add_runtime_dependency 'bootstrap-sass', '~> 3.4.0'
   s.add_runtime_dependency 'font-awesome-sass', '~> 4.6.2'
 
   s.files = [