Pull requests

#	Title	Repository	URL	Creation date	Status
1	Add Git cheatsheet	Hexlet/interactive-courses	https://github.com/Hexlet/interactive-courses/pull/27	25.02.2020	Merged
2	Add PostgreSQL Exercises link	Hexlet/interactive-courses	https://github.com/Hexlet/interactive-courses/pull/26	25.02.2020	Merged