Update README.md

fix typo in markdown
Merge branch 'master' of github.com:jhamman/RVIC into develop
Merge branch 'develop' of github.com:jhamman/RVIC into develop
changes to pandas pour_points dataframe
Merge branch 'develop' of github.com:jhamman/RVIC into develop
fixes to history file and rvar class
Merge branch 'develop' of github.com:jhamman/RVIC into develop