fix(yarn): trim newline from end of yarn output

refs #313
- trims newline so verbose output is nicer

Author: acburdine

lib/utils/yarn.js

@@ -38,7 +38,7 @@ module.exports = function yarn(yarnArgs, options) {
         cp.stdout.setEncoding('utf8');
 
         cp.stdout.on('data', (data) => {
-            observer.next(data);
+            observer.next(data.replace(/\n$/, ''));
         });
 
         cp.then(() => {