[ADAM-367] Updated alias in README.md
Merge pull request #370 from fnothaft/readme-fix

[ADAM-367] Updated alias in README.md
[ADAM-327] Adding Gene, Transcript, and Exon models
Testing and test files.
[TO BE REMOVED] BIG test files.
Added the Alphabet trait and DNAAlphabet implementation.

Updated BlockExtractable to take an Alphabet parameter, and to use the DNAAlphabet by default.
Removing the Gene object, per Uri's suggestion.
Removed Extractable trait on Transcript, and replaced the method with three different methods (again, per Uri's suggestion) for extracting transcript-related sequences.
Upgrade bdg-formats version to 0.2.1-SNAPSHOT
Example GTFParser using the Feature2 schema.
wip