Mcaliley review: typos

• Line 56 of utils.py, in the docstring of rolling_average, it says mind_periods instead of min_periods.

In single_gage_analysis.ipynb:

• hyswap is misspelled in the first sentence.
• "calculate" is misspelled in cell 8.
• Above cell 10, "past" is misspelled and a period is missing between the two sentences.
• Above cell 14, drop the word "a" from "plotting a cumulative hydrographs"

In site_conditions_examples.ipynb:

• Before cell 7 it says that the search is limited to streamgages that have a minimum of 10 years of flow records, but I don't see where that limit is implemented. Maybe I'm missing something?
• Not sure, but I don't think the reference in docs/source/examples/flow_duration_curve_examples.rst to the USGS report titled “Flow-duration curves” by James K. Searcy uses proper citation syntax?

All addressed, thanks for catching these issues!