[WIP] DADA2 1.6 recipe, for Bioconductor 3.6

[benjjneb]

• I have read the guidelines for bioconda recipes.
• This PR adds a new recipe.
• AFAIK, this recipe is directly relevant to the biological sciences (otherwise, please submit to the more general purpose conda-forge channel).
• This PR updates an existing recipe.
• This PR does something else (explain below).

This recipe is building locally on my machine, but fails to install because of missing dependencies. In particular AFAIK bioconda builds of the ShortRead and BiocParallel packages are not yet available for R 3.4.1, and are blocking this package from being bioconda installable, but there may be other such still unbuilt dependencies.

This recipe, and the updated version of the DADA2 R package it builds, address #5457 and are important for downstream use in the QIIME2 microbiome analysis platform.

[ebolyen]

Should the min-version for bioconductor-shortread be bumped to 1.36.0 or is there some other mechanism for syncing the bioconductor packages together?

[daler]

@benjjneb shortread and biocparallel should be available:

• https://anaconda.org/bioconda/bioconductor-shortread/files
• https://anaconda.org/bioconda/bioconductor-biocparallel/files

However the recipes are not currently in master. We've been working on the bulk branch to get everything up-to-date for BioC 3.6. Once that update is complete, the recipes will be merged back into master. But the packages themselves are uploaded as soon as they are successfully built on the bulk branch, which for these packages was within the past week or so.

@ebolyen we finally have a system in place to update packages when a new BioC release comes out. By far the limiting factor is our time on travis-ci -- it has been taking weeks to update everything. We will eventually have a mechanism for watching BioC for point releases of packages to build updated recipes when they're released, but that's longer-term.

[druvus]

those were added in the bulk update (#6800) so I am closing.