attempt to fix travis

Author: david-driscoll

.travis.yml

@@ -1,15 +1,16 @@
 language: csharp
 sudo: required
 dist: trusty
-mono: beta
+mono: latest
 dotnet: 2.0.0
 os:
   - linux
-# env:
-#   global:
-#     secure: m2PtYwYOhaK0uFMZ19ZxApZwWZeAIq1dS//jx/5I3txpIWD+TfycQMAWYxycFJ/GJkeVF29P4Zz1uyS2XKKjPJpp2Pds98FNQyDv3OftpLAVa0drsjfhurVlBmSdrV7GH6ncKfvhd+h7KVK5vbZc+NeR4dH7eNvN/jraS//AMJg=
-
-# windows subsystem for linux doesn't seem to chmod properly when on a windows drive :(
+  - osx
+before_install:
+  - git fetch --unshallow
+cache:
+  directories:
+    - tools
 script:
   - chmod 755 ./build.sh
   - ./build.sh