Attempt to make coverage working again.
diff --git a/.travis.yml b/.travis.yml
index d4472f2..65790db 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -66,6 +66,7 @@
 
 before_install:
   - pip install --user cpp-coveralls
+  - pip install --user requests[security]
     # Lua is not installed on Travis OSX
   - if [ "$TRAVIS_OS_NAME" = "osx" ]; then brew install lua; export LUA_PREFIX=/usr/local; fi