[Tests] Fix cache for WITHOUT_CURL tests in Travis

.travis.yml

@@ -32,7 +32,7 @@ script:
   - if [ -n "${SHELLCHECK-}" ]; then shellcheck -s bash nvm.sh && shellcheck -s sh nvm.sh && shellcheck -s dash nvm.sh && shellcheck -s ksh nvm.sh ; fi
   - if [ -n "${SHELLCHECK-}" ]; then shellcheck -s bash install.sh bash_completion nvm-exec ; fi
   - if [ -n "${SHELL-}" ] && [ -n "${TEST_SUITE}" ]; then make TEST_SUITE=$TEST_SUITE URCHIN="$(npm bin)/urchin" test-$SHELL ; fi
-after_success:
+before_cache:
   - if [ -n "$WITHOUT_CURL" ]; then sudo apt-get install curl -y ; fi
 env:
   global: