Adds a postinstall script that initializes bowerrc

If .bowerrc file does not exist in the installing
project, it'll instantiate one.

This implementation has one goofy blind spot: in the event that
the grandparent of your actual project directory happens to 
contain a "package.json" file, you're going to get a .bowerrc 
up there. Oops. This would be avoided if it were clear npm had
a way for an installing module to know where the root was.

Fixes #3

Author: searls

lib/initializes-bowerrc.coffee

@@ -0,0 +1,28 @@
+fs = require('fs')
+path = require('path')
+
+module.exports =
+  initialize: (dir = process.cwd()) ->
+    return unless (topDir = findTopPackageJson(dir)) && (topDir != dir)
+    return if fs.existsSync(dest = path.join(topDir, '.bowerrc'))
+    console.log("Writing a default '.bowerrc' file into '#{topDir}'")
+    fs.writeFileSync dest, """
+                           {
+                             "directory": "/vendor/bower"
+                           }
+
+                           """
+
+findTopPackageJson = (dir) ->
+  current = path.resolve(dir)
+  grandparent = path.resolve(dir, "..", "..")
+  if current == grandparent || !hasPackageJson(grandparent)
+    if hasPackageJson(current)
+      current
+    else
+      null
+  else
+    findTopPackageJson(grandparent)
+
+hasPackageJson = (dir) ->
+  fs.existsSync(path.join(dir, "package.json"))

package.json

@@ -7,6 +7,9 @@
     "name": "Justin Searls",
     "company": "Test Double"
   },
+  "scripts": {
+    "postinstall": "node script/postinstall.js"
+  },
   "repository": {
     "type": "git",
     "url": "git://github.com/testdouble/lineman-bower.git"

script/postinstall.js

@@ -0,0 +1,4 @@
+require('coffee-script')
+initializesBowerrc = require('./../lib/initializes-bowerrc')
+
+initializesBowerrc.initialize()