Fix: allow weights in SqrNormL2 to be zero

[lostella]

Fixes #139

[codecov]

Codecov Report

Merging #140 (4339337) into master (7c029e9) will decrease coverage by 0.21%.
The diff coverage is 100.00%.

❗ Current head 4339337 differs from pull request most recent head 034ed18. Consider uploading reports for the commit 034ed18 to get more accurate results

@@            Coverage Diff             @@
##           master     #140      +/-   ##
==========================================
- Coverage   95.88%   95.67%   -0.22%     
==========================================
  Files          79       79              
  Lines        2382     2312      -70     
==========================================
- Hits         2284     2212      -72     
- Misses         98      100       +2     

Impacted Files	Coverage Δ
src/functions/sqrNormL2.jl	100.00% <100.00%> (ø)
src/functions/nuclearNorm.jl	96.00% <0.00%> (-4.00%)	⬇️
src/functions/indPolyhedral.jl	80.00% <0.00%> (-3.34%)	⬇️
src/functions/indBallRank.jl	96.87% <0.00%> (-3.13%)	⬇️
src/functions/indFree.jl	75.00% <0.00%> (-2.78%)	⬇️
src/utilities/linops.jl	67.50% <0.00%> (-2.27%)	⬇️
src/functions/indSphereL2.jl	74.19% <0.00%> (-0.81%)	⬇️
src/functions/sqrHingeLoss.jl	75.00% <0.00%> (-0.76%)	⬇️
src/functions/cubeNormL2.jl	94.73% <0.00%> (-0.51%)	⬇️
src/calculus/epicomposeGramDiagonal.jl	92.85% <0.00%> (-0.48%)	⬇️
... and 38 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7c029e9...034ed18. Read the comment docs.