Dike

Added:
* Package API declared stable.

Added:
* New retry decorator for retries of coroutine calls.

Added:
* Doctests to ensure the examples in the documentation keep being correct

Fixed:
* A potential memory leak in case was fixed. It could occur if one of the tasks waiting for the
result of a function decorated with batch was cancelled.

Changed:
* Decorators are now implemented in submodules. The public interface is unchanged

Added:
* Support for numpy arrays in the batch decorator

Added:
* Propagation of function exceptions to all callers for the batch decorator
* A dockerized example service using minibatching and load shedding

Fixed:
* Occasional Python 3.8 f-strings were replaced by a Python 3.7 compatible implementation
* A race condition was fixed that occurred in case of multiple concurrent calls running into the
max_waiting_time at the same moment

Added:
* New batch decorator for minibatching of coroutine calls.
* New limit_jobs decorator to limit the number of concurrent calls to a coroutine function.