Create .npmignore to fix broken release with yarn

.npmignore

@@ -0,0 +1,42 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+docs/
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+coverage.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules
+jspm_packages
+
+# Optional npm cache directory
+.npm
+
+# Optional REPL history
+.node_repl_history
+
+# jsdoc
+doc/