Updated Z3 version in Corral CI to 4.8.8

Author: zvonimir

.travis.yml

@@ -7,7 +7,7 @@ git:
 env:
   global:
     - SOLUTION=cba-NetCore.sln
-    - Z3URL=https://github.com/Z3Prover/z3/releases/download/z3-4.8.4/z3-4.8.4.d6df51951f4c-x64-ubuntu-14.04.zip
+    - Z3URL=https://github.com/Z3Prover/z3/releases/download/z3-4.8.8/z3-4.8.8-x64-ubuntu-16.04.zip
     # Workaround for GitVersionTask bug in combination with .NET Core SDK 3.1.200
     # (see, e.g., https://github.com/dotnet/sdk/issues/10878 and https://github.com/GitTools/GitVersion/issues/2063)
     - MSBUILDSINGLELOADCONTEXT=1