fix missing snapshot.packages in build hybridapp

this commit fixes missing build.snapshot.packages described below

per Ji Liang 1/10 email: 

Expected-- as of mojito 0.4 (mojito 0.4.8-31) when run as mojito hybrid
build the packages info in snapshot.json is like:

```
"packages": {
	"yahoo.libs.yui": "3.4.1",
	"yahoo.application.test04": "0.0.2"
}
```

Actual:
```
"packages": {
	"yahoo.application.test05": "0.0.1"
}
```