Fixes this error:
```
ERROR: yaml.parser.ParserError: while parsing a block mapping
in "./tools/docker-compose/unit-tests/docker-compose.yml", line 10, column 7
expected <block end>, but found '<scalar>'
in "./tools/docker-compose/unit-tests/docker-compose.yml", line 11, column 40
```
The SWIG_FEATURES environment variable is to get pip install working with M2Crypto==0.22.3. It works without SWIG_FEATURES if we update to M2Crypto >= 0.23.0.
Also did some organization, add README.