Fix inv method for RodriguesParam

[hyrodium]

This PR fixes #154.

[codecov-commenter]

Codecov Report

Merging #156 (fa29dc6) into master (38b208b) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #156      +/-   ##
==========================================
+ Coverage   85.40%   85.41%   +0.01%     
==========================================
  Files          12       12              
  Lines        1261     1262       +1     
==========================================
+ Hits         1077     1078       +1     
  Misses        184      184              

Impacted Files	Coverage Δ
src/rodrigues_params.jl	98.63% <100.00%> (+0.01%)	⬆️

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[hyrodium]

julia> R = RodriguesParam(1,2,3)
3×3 RodriguesParam{Int64} with indices SOneTo(3)×SOneTo(3)(1, 2, 3):
 -0.733333  -0.133333  0.666667
  0.666667  -0.333333  0.666667
  0.133333   0.933333  0.333333

julia> inv(R)
3×3 RodriguesParam{Int64} with indices SOneTo(3)×SOneTo(3)(-1, -2, -3):
 -0.733333   0.666667  0.133333
 -0.133333  -0.333333  0.933333
  0.666667   0.666667  0.333333