annotate_metadata_with_index raises ValueError when dtypes don't match #948
Description
Current Behavior
Within annotate_metadata_with_index, the index TSV is read without explicitly set dtypes. This can lead to numerical id strain values to be interpreted as numbers, leading to a ValueError when merging with the metadata.
Additional context
See error reported by user: https://discussion.nextstrain.org/t/value-error-trying-to-merge-on-object-and-int64-columns/1106