package: keep the patch version of deps loose

This will prevent duplicate copies of `mkdirp`
(and possibly others) from being installed at the same time:

```
├─┬ mocha@1.4.2
│ ├── commander@0.6.1
│ ├── debug@0.7.0
│ ├── diff@1.0.2
│ ├── growl@1.5.1
│ ├─┬ jade@0.26.3
│ │ └── mkdirp@0.3.0
│ └── mkdirp@0.3.3
```

turns to:

```
├─┬ mocha@1.5.0
│ ├── commander@0.6.1
│ ├── debug@0.7.0
│ ├── diff@1.0.3
│ ├── growl@1.5.1
│ ├── jade@0.27.5
│ ├── mkdirp@0.3.4
│ └── ms@0.3.0
```