Allow imposing different boundary conditions on each side

[codecov-commenter]

Codecov Report

Merging #70 (7f388e4) into master (430783a) will increase coverage by 0.08%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #70      +/-   ##
==========================================
+ Coverage   95.11%   95.19%   +0.08%     
==========================================
  Files          34       34              
  Lines        2149     2166      +17     
==========================================
+ Hits         2044     2062      +18     
+ Misses        105      104       -1     

Impacted Files	Coverage Δ
src/Recombinations/matrices.jl	95.96% <100.00%> (+0.52%)	:arrow_up:
src/Recombinations/splines.jl	100.00% <100.00%> (ø)