Kernel#methods should not return method_missing stubs
Merge pull request #530 from mieko/ignore_method_stubs

Kernel#methods should not return method_missing stubs
Be sure to release any executable from bin/
Improve missing nodejs CLI exception name
Add `opal-build` command utility to build libs to js
Add specs for opal/sprockets

Partly ported from opal-rails.
Update RSpec rc file
Clearly mark sprockets boilerplate code
Reposition Opal.process implementation to "environment.rb"
Update the readme with latest spec/ updates info

[ci skip]
Changed expect_compiled to be just a wrapper around Opal::Compiler
Compiles require into Javascript as a no-op
Added "requirable" to compiler options to mark files for future requires
Enter New Builder
Cleanup path_finder stubs
Add path_finder lint shared example
Fix requires in spec/cli
Add path_reader and hike_path_finder
Let require be compiled to js
Add require support to runtime/kernel