Use msgpack git master to support PHP 7.1

sodabrew · sodabrew · commit 56845602fbc3 · 2016-10-10T14:20:42.000-07:00
diff --git a/.travis/travis.sh b/.travis/travis.sh
@@ -239,7 +239,8 @@ case $ACTION in
         install_igbinary
 
         # Install msgpack extension
-        pecl install msgpack-2.0.1
+        install_msgpack
+        # pecl install msgpack-2.0.1
 
         install_memcached
         run_memcached
