R `svyrep` algorithms source code

[smishr]

svyrep has the R code for many of the algorithms we have tried implementing in Julia for replicate designs.

• [ ] line 31 - jk1weights
• [ ] line 73 - jknweights
• [ ] line 165 - brrweights
• [ ] as.svrepdesign and svyrepdesign of which currently we have only implemented bootstrap, out of the 8 or so kinds of replicate weights which R does.
• [ ] line 702 - svrVar - which is a general function to calculate variance using rep designs.
• [ ] line 1396 - svyrepratio for ratio estimation
• [ ] line 1832 - poststratify
• [ ] line 1915 - rake
• [ ] ... and many more helper utilities functions etc

Attempt to implement above functionalities in Julian design.