Fix: use absolute path in CLITests.test_generate_config
Fix: use absolute path in CLITests.test_generate_config

Previously, the expected path of the test was hardcoded to
/vagrant/testfile which caused failures in travis.

cimarron-pistoncloud/gitlint,slipcon/gitlint,jorisroovers/gitlint,cimarron-pistoncloud/gitlint,slipcon/gitlint,jorisroovers/gitlint