Renamed RPFloatLabeledTextView to RPFloatingPlaceholders, bumped to v0.2

I removed the old podspec since it was an alpha.  This is the final version of it with the final name.

```shell
pod spec lint RPFloatingPlaceholders.podspec

 -> RPFloatingPlaceholders (0.2)

Analyzed 1 podspec.

RPFloatingPlaceholders.podspec passed validation.
```