added support for resolutions

Alphabetized method names and added support for resolutions to ensure dependencies are resolved using specific version, i.e.

``` ruby
resolution "angular", "1.2.22"
```

```
bx rake bower:install
```

Will output into bower.json

``` javascript
{
  "name" : "dsl-generated dependencies",
  "dependencies" : {
    "angular" : "1.2.22"
  },
  "resolutions": {
    "angular": "1.2.22"
  }
}
```