Switch from yarn to npm

.yarnclean

@@ -1,45 +0,0 @@
-# test directories
-__tests__
-test
-tests
-powered-test
-
-# asset directories
-docs
-doc
-website
-images
-assets
-
-# examples
-example
-examples
-
-# code coverage directories
-coverage
-.nyc_output
-
-# build scripts
-Makefile
-Gulpfile.js
-Gruntfile.js
-
-# configs
-appveyor.yml
-circle.yml
-codeship-services.yml
-codeship-steps.yml
-wercker.yml
-.tern-project
-.gitattributes
-.editorconfig
-.*ignore
-.eslintrc
-.jshintrc
-.flowconfig
-.documentup.json
-.yarn-metadata.json
-.travis.yml
-
-# misc
-*.md