Follow up to #337 that further loosens setup.py requirements.
The JAVA_HOME env var is now optional: if it's not defined, we try to derive the JDK home from the java.home system property. If this fails for any reason, we fall back to asking for JAVA_HOME as we did before.
All logic that requires Java home info has been moved to the build phase, allowing other setup commands to run with (almost) no requirements. For instance, we can now run python setup.py sdist from Travis.
The HADOOP_HOME env var is now explicitly optional. In this case we already had auto-detection logic in place, but now the docs make it clear.
Follow up to #337 that further loosens
setup.pyrequirements.JAVA_HOMEenv var is now optional: if it's not defined, we try to derive the JDK home from thejava.homesystem property. If this fails for any reason, we fall back to asking forJAVA_HOMEas we did before.python setup.py sdistfrom Travis.HADOOP_HOMEenv var is now explicitly optional. In this case we already had auto-detection logic in place, but now the docs make it clear.