Rename (merge) underscore-transducer into underarm

[kevinbeaty]

Move functionality of underscore-transducer into underarm and deprecate underscore-transducer name. This does NOT deprecate underscore-transducer. Think of it as a rename of underscore-transducer to underarm.

Most functionality in underscore-transducer has been extracted into transduce and the distinction between this package and underarm is mostly arbitrary. underscore-transducer started as an exploration of transducers inspired by the old underarm API which was in turn inspired by underscore.

There is little point in maintaining an "underscore inspired" transducers API under both names. Subsets of functionality can be created with custom builds. This will also reduce confusion whether underscore-transducer is compatible with underscore and/or lodash (it is not, just inspired by the API).

The github repo and npm module will not be removed/unpublished, but will be deprecated and point to underarm.