clean up method name: [NyaruDB collectionForName:] -> [NyaruDB collection:]

[NyaruDB collectionForName:] will be removed in 1.4.
replace [NyaruDB collectionForName:name] with [NyaruDB collection:name] in unittest.
clean up method name: [NyaruCollection insert:] -> [NyaruCollection put:]

[NyaruCollection insert:] will be removed in 1.4
Merge pull request #5 from kelp404/1.3.4

1.3.4
[NyaruDB collection:]
[NyaruCollection put:]