Ensembl gene annotations not uniform

[aiqc]

If it's possible for multiple ensembl values to be returned, then they should always be a list.

When using fields="symbol,ensembl.type_of_gene"

[
{
    'query': 'ENSG00000283341',
    '_id': 'ENSG00000283341',
    '_version': 1,
    'ensembl': {'type_of_gene': 'lncRNA'}
},
{
    'query': 'ENSG00000199352', 
    '_id': '100169751',
    '_version': 2, 
    'ensembl': [{'type_of_gene': 'rRNA'}, {'type_of_gene': 'rRNA'}], 
    'symbol': 'RNA5S1'
}
]