Update AdapterRemoval with skip 5prime trimming

[jfy133]

The latest version of AdapterRemoval now has a new flag related to issues identified with erroneous trimming of 5 prime ends leading to true PCR duplicates not being removed.

We need to

a) bump the AR version in the environment
b) add the --preserve5p flag to EAGER2 options

[jfy133]

And thanks @maxibor for the reminder to post this ;)

[apeltzer]

Yeah given that the bioconda recipe is already updated, we could probably push this in very quickly!

[jfy133]

Added in #255