patch 7.4.2146
Problem:    Not enough testing for popup menu.  CTRL-E does not always work
            properly.
Solution:   Add more tests.  When using CTRL-E check if the popup menu is
            visible. (Christian Brabandt)
diff --git a/.travis.yml b/.travis.yml
index 13ad376..0acbf90 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -62,6 +62,7 @@
       - python3-dev
       - liblua5.1-0-dev
       - lua5.1
+      - cscope
 
 before_install:
   - pip install --user cpp-coveralls