Update .gitignore to ignore IntelliJ files
Merge branch 'master' of https://github.com/nitinpunjabi/clj-ctci

Conflicts:
	.gitignore
	.idea/workspace.xml
Refresh .gitignore file
Implement higher order permutation check function
Implement permutation check through sorting
Implement a permutation check using character frequencies
Implement tests for sort-check
Implement tests for freq-check