explicit ssreflect version in Travis

Author: palmskog

.travis-ci.sh

@@ -8,6 +8,7 @@ opam repo add coq-core-dev https://coq.inria.fr/opam/core-dev
 opam repo add coq-extra-dev https://coq.inria.fr/opam/extra-dev
 
 opam pin add coq $COQ_VERSION --kind=version --yes --verbose
+opam pin add coq-mathcomp-ssreflect $SSREFLECT_VERSION --kind=version --yes --verbose
 
 opam pin add Heaps --yes --verbose
 opam pin add Core --yes --verbose

.travis.yml

@@ -9,7 +9,7 @@ addons:
       - aspcud
 env:
   matrix:
-    - COQ_VERSION=8.7.0
+    - COQ_VERSION=8.7.0 SSREFLECT_VERSION=1.6.4
 script: bash -ex .travis-ci.sh
 sudo: false
 notifications: