Using H2O_HOSTS_FILE to point to host file location.
Small refactoring regarding test.py.

The test was moved into testdir_multi_jvm, will be call as a part of
multi jvm nightly.
Test junit contains slow tests.

The file will be probably removed and replaced
by call of junit runner.
Sandbox name can be configured by an env var.

Environment can introduce name of sandbox by variable H2O_SANDBOX_NAME
Merge branch 'master' of github.com:0xdata/h2o