Add node-pre-gyp path to search paths

Fixes #11.
Closes #32.

Squashed commit of the following:

commit d58451e
Author: Bryan Knight <[email protected]>
Date:   Thu Mar 2 14:03:50 2017 -0500

    Add node-pre-gyp path to search paths

    The node-pre-gyp docs have the binary go into `./lib/binding/{node_abi}-{platform}-{arch}`

Co-authored-by: Bryan Knight <[email protected]>

bindings.js

@@ -15,6 +15,7 @@ var fs = require('fs')
       , compiled: process.env.NODE_BINDINGS_COMPILED_DIR || 'compiled'
       , platform: process.platform
       , arch: process.arch
+      , nodePreGyp: 'node-v' + process.versions.modules + '-' + process.platform + '-' + process.arch
       , version: process.versions.node
       , bindings: 'bindings.node'
       , try: [
@@ -37,6 +38,8 @@ var fs = require('fs')
         , [ 'module_root', 'addon-build', 'release', 'install-root', 'bindings' ]
         , [ 'module_root', 'addon-build', 'debug', 'install-root', 'bindings' ]
         , [ 'module_root', 'addon-build', 'default', 'install-root', 'bindings' ]
+          // node-pre-gyp path ./lib/binding/{node_abi}-{platform}-{arch}
+        , [ 'module_root', 'lib', 'binding', 'nodePreGyp', 'bindings' ]
         ]
     }