bump Iris; add missing concurrent_stacks to _CoqProject

_CoqProject

@@ -14,6 +14,11 @@ theories/spanning_tree/mon.v
 theories/spanning_tree/spanning.v
 theories/spanning_tree/proof.v
 
+theories/concurrent_stacks/concurrent_stack1.v
+theories/concurrent_stacks/concurrent_stack2.v
+theories/concurrent_stacks/concurrent_stack3.v
+theories/concurrent_stacks/concurrent_stack4.v
+
 theories/logrel/prelude/base.v
 theories/logrel/stlc/lang.v
 theories/logrel/stlc/typing.v

opam

@@ -9,6 +9,6 @@ build: [make "-j%{jobs}%"]
 install: [make "install"]
 remove: ["rm" "-rf" "%{lib}%/coq/user-contrib/iris_examples"]
 depends: [
-  "coq-iris" { (= "dev.2018-01-21.0") | (= "dev") }
+  "coq-iris" { (= "dev.2018-02-15.0") | (= "dev") }
   "coq-autosubst" { = "dev.coq86" }
 ]