Test calling the scheduler

[Flix6x]

Closes #3.

• Start namespace for S2 AssetTypes
• Add fixtures for setting Asset attributes that the scheduler will require
• Add first test for schema validation
• Add first test for calling scheduler directly
• Add first test for calling scheduler via API

Todo @VladIftime:

• Where it says # todo: port test cases from Java test please add at least one example of the profile you found in the Java code, then let me know and we can discuss how to adjust the schemas to make that test pass.
• Where it says # todo: add serialized state please assign the serialized state to a variable in a separate Python file and then import the variable here. Otherwise, the conftest.py will become too large. Then we can start adjusting the S2FlexModelSchema to use the s2-python library.

[Flix6x]

Just a pointer. Thanks for creating the example JSON.

[Flix6x]

Let's define two variables here:

• example_serialized_device_state, which loads the JSON you added. This variable is the one that the conftest should import, because we want to store a serialized state on the asset attributes
• example_deserialized_device_state, which is the object you already defined here. This variable could be used in a new schema test, as an expected outcome of loading (i.e. deserializing) example_serialized_device_state using the S2FlexModelSchema`.

[Flix6x]

Going in the right direction.

[Flix6x]

assert scheduler.deserialize_config().flex_model == example_deserialized_device_state?

[Flix6x]

What's the status on this PR?

[Flix6x]

We discussed moving one of the test devices from #5 into this PR. @VladIftime, did you mean this test device?