add opam specialized solver, fix up Travis script

Author: palmskog

.travis-ci.sh

@@ -10,12 +10,12 @@ verdi)
   opam install coq-mathcomp-ssreflect.$SSREFLECT_VERSION --yes --verbose
 
   pushd ..
-    git clone 'http://github.com/uwplse/StructTact'
+    git clone 'https://github.com/uwplse/StructTact.git'
     pushd StructTact
       ./build.sh
     popd
 
-    git clone 'http://github.com/uwplse/verdi'
+    git clone 'https://github.com/uwplse/verdi.git'
     pushd verdi
       ./build.sh
     popd

.travis.yml

@@ -7,6 +7,7 @@ addons:
     packages:
       - ocaml
       - opam
+      - aspcud
 env:
   global:
     - COQ_VERSION=8.5.3