[RELEASE] Version 0.2.0

Changelog:
  * Fix flat frequency response for biquad filter
  * Renaming 'AnalysisWindow' class to 'Window' in analysis module
  * Better documentation (include classes constructors)
  * New filters: single pole, state variable, parametric equalizer
[MISC] Add feature list to README
[DEV] Add new delay module with DelayLine class
[DEV] Fix Python2 compatibility for previous commit (implicit int/float conversions)
[DOCS] Add rst doc file for delay module
[DEV] Add process sample method in DelayLine class
[DEV] Add clear method for DelayLine class
[DEV] Add Comb filtering to filter module
[DEV] Add convolution filtering in filter module
[DEV] Add Fast Convolution in filter module
[LINT] Remove whitespace in blank line
[DEV] Fix convolution with IR longer than signal block
[MISC] Update README with new filters (Comb, Convolution)
[TEST] Add main entry point for comb filter unit testing module
[DEV] Add Custom Filter in filter module
[MISC] Update README with new Custom filter
[DEMO] Add Custom Filter Design demo
[DEV] Forgotten yodel.conversion import in filter module
[DEV] Add Windowed Sinc filter in filter module
[DEV] Fix windowed sinc filter kernel computations