Bash file ./marathon created

* Also README.md was updated with cli usage
Merge branch 'master' of github.com:gextech/marathon-runner
Installing file in process

Using as base nvm install.sh I have coded marathon install.sh, I think it is ok, it creates MARATHON_DIR, and clone project into MARATHON_SOURCES, but script marathon.sh is not working correctly witg gradlew =/ I need to work on this later...
Merge branch 'master' of github.com:anallely/marathon-runner
Gradle task buildZip

Generates marathon.zip which contains:
   - libs/cli-${currentVersion}-all.jar
   - bin/marathon                           # Executable file
Merge pull request #18 from anallely/master

Gradle task buildZip