Stratified resampling

[simsurace]

This is an experimental branch with the following changes:

• A new feature that allows one to set the resampling method as a keyword parameter resampling_method of NestedFilterSimulation.
• The previous sampling algorithm is the default option, now called Multinomial()
• When setting resampling_method = Stratified(), the stratified resampling scheme from this paper is used.
• In the /exp folder, there is a script and resulting figures showing the convergence of parameter estimates for the two resampling methods.

[codecov]

Codecov Report

Merging #77 (0dcaea1) into master (c2101b0) will decrease coverage by 8.12%.
The diff coverage is 10.90%.

@@            Coverage Diff             @@
##           master      #77      +/-   ##
==========================================
- Coverage   69.07%   60.96%   -8.12%     
==========================================
  Files          14       15       +1     
  Lines         692      789      +97     
==========================================
+ Hits          478      481       +3     
- Misses        214      308      +94     

Impacted Files	Coverage Δ
src/BinomialSynapses.jl	100.00% <ø> (ø)
src/resample.jl	35.43% <5.82%> (-20.20%)	⬇️
src/filter.jl	93.33% <66.66%> (-6.67%)	⬇️
src/likelihood.jl	93.75% <100.00%> (ø)
src/simulate.jl	86.44% <100.00%> (ø)

... and 1 file with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more