gnu: Add porechop.

* gnu/packages/bioinformatics.scm (porechop): New variable.

gnu/packages/bioinformatics.scm

@@ -13869,3 +13869,33 @@ (define-public r-bseqsc
 and intra-cell population structure.\" Baron et al. Cell Systems (2016)
 @url{https://www.ncbi.nlm.nih.gov/pubmed/27667365}.")
       (license license:gpl2+))))
+
+(define-public porechop
+  ;; The recommended way to install is to clone the git repository
+  ;; https://github.com/rrwick/Porechop#installation
+  (let ((commit "289d5dca4a5fc327f97b3f8cecb68ecaf1014861")
+        (revision "1"))
+    (package
+      (name "porechop")
+      (version (git-version "0.2.3" revision commit))
+      (source
+       (origin
+         (method git-fetch)
+         (uri (git-reference
+               (url "https://github.com/rrwick/Porechop.git")
+               (commit commit)))
+         (file-name (git-file-name name version))
+         (sha256
+          (base32 "05ps43gig0d3ia9x5lj84lb00hbsl6ba9n7y7jz927npxbr2ym23"))))
+      (build-system python-build-system)
+      (home-page "https://github.com/rrwick/porechop")
+      (synopsis "Finding, trimming or splitting adapters, in Oxford Nanopore reads")
+      (description
+       "The porechop package is a tool for finding and removing adapters from Oxford
+Nanopore reads.  Adapters on the ends of reads are trimmed off, and when a read
+has an adapter in its middle, it is treated as chimeric and chopped into
+separate reads.  Porechop performs thorough alignments to effectively find
+adapters, even at low sequence identity.  Porechop also supports demultiplexing
+of Nanopore reads that were barcoded with the Native Barcoding Kit, PCR
+Barcoding Kit or Rapid Barcoding Kit.")
+      (license license:gpl3+))))