add empty file for dgram core module

closes #11
0.0.5
failing test for `false` browser field values
use empty.js target for `false` shims; false test passes
examples
readme example headings
skip example
use tar example for false option
Merge pull request #14 from substack/false

support `false` as a browser field value, added examples
0.1.0
update dependencies: resolve, http, buffer
0.1.1
updated querystring
Merge pull request #16 from juliangruber/querystring

updated querystring
remove core module shims

browser-resolve is only responsible for handling the browser field
resolution. Consumers of this module who wish to provide alternatives to
the core node modules should specify a `modules` option when calling
resolve. The modules object is a key/value of core modulename -> path.
1.0.0
support legacy browserify field

closes #18
1.0.1
Include file path in error message
Merge pull request #21 from timoxley/patch-1

Include file path in error message for package.json syntax errors