Simplify the regex used

It doesn't matter which path separator is used, no need to save it in a
capturing group.

lib/helpers.js

@@ -3,25 +3,25 @@
 import {BufferedProcess} from 'atom'
 const extractionRegex = /Installing (.*?) to .* (.*)/
 const nameRegexes = [
-  /(\\|\/)packages(\\|\/)(.*?)(\\|\/)/,
-  /(\\|\/)([\w-_]+)(\\|\/)(lib|src)(\\|\/)/i,
-  /(\\|\/)([\w-_]+)(\\|\/)[\w-_]+\..+$/
+  /[\\\/]packages[\\\/](.*?)[\\\/]/,
+  /[\\\/]([\w-_]+)[\\\/](?:lib|src)[\\\/]/i,
+  /[\\\/]([\w-_]+)[\\\/][\w-_]+\..+$/
 ]
 
 export function guessName(filePath) {
   let matches
 
   matches = nameRegexes[0].exec(filePath)
   if (matches) {
-    return matches[3]
+    return matches[1]
   }
   matches = nameRegexes[1].exec(filePath)
   if (matches) {
-    return matches[2]
+    return matches[1]
   }
   matches = nameRegexes[2].exec(filePath)
   if (matches) {
-    return matches[2]
+    return matches[1]
   }
   return null
 }