Merge pull request #15 from lowjoel/javascript

Fix casing for the display name.

Author: ALLEN WANG QIANG

lib/coursemology/polyglot/language/java_script.rb

@@ -1,4 +1,4 @@
 class Coursemology::Polyglot::Language::JavaScript < Coursemology::Polyglot::Language
   syntax_highlighter 'javascript'
-  concrete_language 'javascript', docker_image: 'javascript'
+  concrete_language 'JavaScript', docker_image: 'javascript'
 end