Allow tests to fail under emacs-git-snapshot

Cask seems to currently be broken with Emacs git.

.travis.yml

@@ -15,6 +15,7 @@ env:
 matrix:
   allow_failures:
   - env: EMACS_VERSION=remacs-git-snapshot
+  - env: EMACS_VERSION=emacs-git-snapshot
 
 before_script:
   # Install evm