Fixed:
* Fix fetching tab names that are like cells (e.g. "TSA1") (124)
* Fix behavior for renamed sheets (125)
Changes (121):
* COGS will create an empty file at a location if a path specified by `add` does not exist
* You can now specify a path for an ignored sheet
* `connect` fetches all data after initializing the COGS directory
* You can mv into a directory just by passing the directory name (e.g., `cogs mv foo.tsv bar/`)
* `mv` does not rename the sheet title, unless specified by `--title`
* `rm` deletes local copies, unless the `--keep` flag is included