Dispatch pullback rrule for all Invertible

[ziyiyin97]

Fix #60

[codecov]

Codecov Report

Merging #62 (7229577) into master (192a7fe) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #62      +/-   ##
==========================================
+ Coverage   88.11%   88.14%   +0.03%     
==========================================
  Files          31       31              
  Lines        2330     2328       -2     
==========================================
- Hits         2053     2052       -1     
+ Misses        277      276       -1     

Impacted Files	Coverage Δ
src/utils/jacobian.jl	81.81% <ø> (ø)
src/utils/chainrules.jl	91.48% <100.00%> (ø)
src/utils/invertible_network_sequential.jl	89.70% <100.00%> (ø)
src/utils/neuralnet.jl	75.55% <100.00%> (+1.08%)	⬆️

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[ziyiyin97]

Any thought?