Merge pull request #1 from ghoseb/master

Refactor.
Merge pull request #2 from ghoseb/master

Enhance read-config's API and update README
Merge pull request #3 from ghoseb/master

Add write-config
Re-enabled all tests - and also, trim spaces from the end of the values.
Remove use of slurp in load-props.

Fix test cases.
Add read-config-str fn that reads from a Properties string.

Add related test-cases.
Minor cleanup to remove duplication in argument handling in read-config-str, and test for write-config
Removed the mock function and now we test only the read-config-str function in all cases except one where we test with a real file.
Reverted a previous change - seeing arguments-info in the docs is a better idea!
Updated README for a couple of examples to point to the checked-in test.properties file as an example.