* attribute-based heterogeneity-awareness in global scheduler and photon
* minor post-rebase fix
* photon: enforce dynamic capacity constraint on task dispatch
* globalsched: cap the number of times we try to schedule a task in round robin
* propagating ability to specify resource capacity to ray.init
* adding resources to remote function export and fetch/register
* globalsched: remove unused functions; update cached photon resource capacity (until next photon heartbeat)
* Add some integration tests.
* globalsched: cleanup + factor out constraint checking
* lots of style
* task_spec_required_resource: global refactor
* clang format
* clang format + comment update in photon
* clang format photon comment
* valgrind
* reduce verbosity for Travis
* Add test for scheduler load balancing.
* addressing comments
* refactoring global scheduler algorithm
* Minor cleanups.
* Linting.
* Fix array_test.py and linting.
* valgrind fix for photon tests
* Attempt to fix stress tests.
* fix hashmap free
* fix hashmap free comment
* memset photon resource vectors to 0 in case they get used before the first heartbeat
* More whitespace changes.
* Undo whitespace error I introduced.
* Split local scheduler task queue into waiting and dispatch queue
* Fix memory leak
* Add a new task scheduling status for when a task has been queued locally
* Fix global scheduler test case and add task status doc
* Documentation
* Address Philipp's comments
* Move tasks back to the waiting queue if their dependencies become unavailable
* Update existing task table entries instead of overwriting
