adding outline for parallel tactic

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/tactic/portfolio/solver2lookahead.cpp

@@ -0,0 +1,24 @@
+/*++
+Copyright (c) 2017 Microsoft Corporation
+
+Module Name:
+
+    solver2lookahead.cpp
+
+Abstract:
+
+    Lookahead wrapper for arbitrary solver.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2017-10-9
+
+Notes:
+   
+--*/
+#include "sat/sat_solver/inc_sat_solver.h"
+#include "solver/solver.h"
+
+solver * mk_solver2lookahead(solver* s) {
+    return 0;
+}