Implement API endpoints for other dataprovider functionality

[davmlaw]

These are client calls:

    def get_acs_for_protein_seq(self, seq):
        raise NotImplementedError()

    def get_gene_info(self, gene):
        raise NotImplementedError()

    def get_pro_ac_for_tx_ac(self, tx_ac):
        raise NotImplementedError()

    def get_similar_transcripts(self, tx_ac):
        raise NotImplementedError()

    def get_tx_for_gene(self, gene):
        # TODO: We could build this from JSON pretty easily
        raise NotImplementedError()

    def get_tx_for_region(self, alt_ac, alt_aln_method, start_i, end_i):
        # TODO: This would be hard to do in Redis but we could do via HTSeq
        raise NotImplementedError()