Spelling and grammar

![img_20170915_230527](https://user-images.githubusercontent.com/31629119/30495852-3ed2406a-9a6b-11e7-8c83-aa22c413fabd.jpg)
- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry
