Extensions to numeric-prelude including multivariate polynomials and factored rationals.

#2inaccurate lower bound on `containers`

np-extras-0.3.1.2 needs containers-0.4.2 or later

Configuring library for np-extras-0.3.1.2..
Preprocessing library for np-extras-0.3.1.2..
Building library for np-extras-0.3.1.2..
[1 of 3] Compiling MathObj.Monomial ( MathObj/Monomial.hs, /tmp/matrix-worker/1547842412/dist-newstyle/build/x86_64-linux/ghc-7.0.4/np-extras-0.3.1.2/build/MathObj/Monomial.o )

MathObj/Monomial.hs:74:21: Not in scope: `M.foldr'
<<ghc: 319466072 bytes, 539 GCs, 9904668/28956688 avg/max bytes residency (6 samples), 61M in use, 0.00 INIT (0.00 elapsed), 0.12 MUT (0.12 elapsed), 0.19 GC (0.19 elapsed) :ghc>>

I've already fixed up the metadata for the affected release at

https://hackage.haskell.org/package/np-extras-0.3.1.2/revisions/