* Changed Shortest Path Follower criteria to use geodesic distance

* Fixed bug with uneven splits for dataset
* Fixed check if test data was loaded for CI

Added proper check of test data installed to fix CI.

This PR seeks to bring habitat-API inline with this. StaticPointGoalSensor is now just a PointGoalSensor and the old PointGoalSensor is now a PointGoalWithGPSCompassSensor. There are also now explicit GPS and Compass sensors, such that you can fairly easily compute PointGoalWithGPSCompassSensor given [PointGoalSensor, GPSSensor, CompassSensor].
The PointGoal* sensors now also include {2d, 3d} x {Cartesian, Polar} support.

Explicitly call close for vector env to avoid issues with file writer prematurely close buffer when tensorboard enabled. See #184 for more info.

Making eval() in ppo_trainer retrieve the name (sensor_uuid) of performance metric used instead of always using spl. This change is necessary for ppo_trainer to support new tasks that might have performance metric other than spl.

With the recent refactor/redesign of habitat_baselines, all experiment parameters can be specified through config files. Thus it makes sense to turn the python script run in circle-ci into a separate test file in our test/. This also makes it more extensible when we add more trainers in the future.

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* before doc

* use iter getter instead of as a dataset attr

* fix docstrings

* changes according to comment

* fix long var name

* use default value in next

* fix baseline test import and docstring

* lr scheduler and tb writer

* refactor config

* More Env typing fixes

* Move log_file config entry

* fix tb-related VectorEnv del bug

* change config entries to list

* fix env class retrieval

* change default opts to empty list

* changes according to comments

* convert jupyter notebooks to sphynx tutorial

* update download links

* habitat-sim demo, update image links

* add documentation link, remove PRs welcome

* nit

* remove habitat-api_structure.png

* Refactor baselines to allow for extension

* Make clip an after-backward

* Loop over rollout step instead of function for full rollout

* Make fog-of-war darker and make that value changeable

Update baseline test import and fix docstring 

* refactor and  add generic trainer class

* fix to pass tests

* change BaseModel to BaseTrainer

* fix tensorboard import causing CI failure

* modify circle-ci test script accordingly

* doc, typing and other changes

* rename BASELINE to TRAINER

* merge from upstream master

* Update Habitat-API to allow for no rendering sensors (#139)

Update Habitat-API to allow for no rendering sensors

* Added installation requirements step for sim installation in CI setup. (#159)

Added installation requirements step for sim installation in CI setup

* move RolloutStorage to utils

* add environments.py

* make ckpt dir if not exist

* small fixes according to comments

* changes according to comments

* update readme

* fix old config compatibility

* fix missed isort lint

* fixed PyTorch caching
* added ccache to CI
* broke habitat api step on installation and testing to save extra 5 min on saving cache in parallel
* testing time drops from first run to second run from 17.5 minutes to 9 minutes (2x times) for full testing.

* Add fog-of-war to topdown map

Make env access episode through iterator

Added installation requirements step for sim installation in CI setup

Update Habitat-API to allow for no rendering sensors

This does the necessary adaptation to facebookresearch/habitat-sim#64 -- this was the only failure in habitat-sim's CI tests

* episode stats changed to dict of dicts

* handle non-unique episode_id

* use tuple as key

* update while loop checking

Co-Authored-By: Erik Wijmans <ewijmans2@gmail.com>

* made simulator actions iterable

* Fix quickstart

* Add checkpoint progress tracking for evalute_ppo. Now when specified with a checkpoint directory,
* Evaluate_ppo will evaluate checkpoints in chronological order, and constantly check for new checkpoint.
* Add tensorboard visualization to both train_ppo and evaluate_ppo
* Add video generation for navigation episode evaluation. Generated videos can be either saved locally or visualized through tensorboard.
* Add shortest path visualization

Updated version to 0.1.2

Limit requirements search scope to habitat_baselines folder.

Fix issue with POINTNAVV1 fix.

SimulatorActions is no longer an enum. It is an extendable singleton. It allows you to extend the action space but it is quite strict about it. Actions cannot be put on different ints, actions cannot be remove.
There is now a registry for action space configurations.

Fix docs typo: step() -> act()

* Modify partitioning logic to handle left-over scenes due to integer division