Merge pull request #16 from utah-geological-survey:frst_str

get_first_string error

Update usgs.py

Updated "M" to "ME" to fix some deprecations in pandas

Create pyproject.toml

Update __init__.py

Update .travis.yml

Update __init__.py

Update __init__.py

Update README.md

version 0.2.21

changes how the gantt class works