first implementation of annotation track

[savitakartik]

adds a basic gene track to the Mutations page when a gene coordinate csv like below is provided
python -m tsqc path/to/trees --annotate-genes path/to/csv

Few issues to iron out:

input annotation file format checks. (I guess it might be better to switch to a standard bed or gtf format file at some point.)
subset annotation data to the same chromosome as tree sequence
restrict y zooming on the genome and tree tracks

[savitakartik]

gene_annotation.mp4

[savitakartik]

Is it ok to update file path in the config file like I've done in main?

if annotate_genes:
        config.GENES_FILE = annotate_genes

or should user directly just provide a path in the config file?

[jeromekelleher]

LGTM! Putting the annotations_file in a global config is a bit icky, but it works for now and I can imagine that being something you just want to set as a default (in your .config/tsqc.conf file, at some point).

[jeromekelleher]

Few minor changes, let's merge then

[savitakartik]

LGTM! Putting the annotations_file in a global config is a bit icky, but it works for now and I can imagine that being something you just want to set as a default (in your .config/tsqc.conf file, at some point).

sure, that makes sense.