fix name of required sqlite3-ocaml package
see also https://github.com/matsen/pplacer/commit/4ae1c6803486a6460a776b6807657a3bcc4005da
--- opam-requirements.txt.orig	2015-10-06 16:38:42.246475661 +0200
+++ opam-requirements.txt	2015-10-06 16:38:50.586708932 +0200
@@ -4,5 +4,5 @@
 mcl.12-068oasis3
 batteries.2.1.0
 ocaml-gsl.0.6.3
-sqlite3-ocaml.1.6.3
+sqlite3.1.6.3
 camlzip.1.05
