Scar

* Extracted supervisor code (now it's an external package used also in other projects, checkout -> https://github.com/grycap/faas-supervisor)
* Added supervisor and udocker as a lambda layer (it's easier to update and allows faster function deployment)
* Refactored properties management
* Removed support to binary version (SCAR is now distributed as a pip package, check 'pip3 install scar')

* Update udocker to new version
* Add alpine image support
* Several bugfixes

* Bugfix in ApiGateway

* Add Batch Job integration (more info [here](https://scar.readthedocs.io/en/latest/batch.html) and [here](https://github.com/grycap/scar/tree/master/examples/video-process))
* Fix several bugs

* Update binary to fix several bugs
* Update Dockerfile to create the binaries and the SCAR container

* Update code to ease the binary usage
* Add udocker bin to the package