move needsIndex to seprate file

Tries to remove cyclical dependency any.js -> psudo.js addressing
[#9](#9)

Author: peterbabic

lib/any.js

@@ -3,7 +3,7 @@
 module.exports = match
 
 var zwitch = require('zwitch')
-var pseudo = require('./pseudo')
+var needs = require('./needs')
 var test = require('./test')
 var nest = require('./nest')
 
@@ -75,7 +75,7 @@ function configure(query, state) {
   var index = -1
 
   while (++index < pseudos.length) {
-    if (pseudo.needsIndex.indexOf(pseudos[index].name) > -1) {
+    if (needs.needsIndex.indexOf(pseudos[index].name) > -1) {
       state.index = true
       break
     }

lib/needs.js

@@ -0,0 +1,19 @@
+/* istanbul ignore file - Shouldn’t be invoked */
+'use strict'
+
+module.exports = match
+
+function match() {}
+
+match.needsIndex = [
+  'first-child',
+  'first-of-type',
+  'last-child',
+  'last-of-type',
+  'nth-child',
+  'nth-last-child',
+  'nth-of-type',
+  'nth-last-of-type',
+  'only-child',
+  'only-of-type'
+]

lib/pseudo.js

@@ -9,19 +9,6 @@ var anything = require('./any')
 
 var is = convert()
 
-match.needsIndex = [
-  'first-child',
-  'first-of-type',
-  'last-child',
-  'last-of-type',
-  'nth-child',
-  'nth-last-child',
-  'nth-of-type',
-  'nth-last-of-type',
-  'only-child',
-  'only-of-type'
-]
-
 var handle = zwitch('name', {
   unknown: unknownPseudo,
   invalid: invalidPseudo,