[Minor] Try to fix CI

circle.yml

@@ -1,9 +1,14 @@
 dependencies:
     pre:
-      - sudo apt-get update -qq
-      - sudo apt-get install -qq cmake gcc lcov libevent-dev libglib2.0-dev libgmime-2.6-dev libluajit-5.1-dev liblua5.1-0-dev libmagic-dev libpcre3-dev libsqlite3-dev libssl-dev make python-dev ragel redis-server redis-tools
+      - sudo apt-get update -qq || true
+      - sudo apt-get install -qq cmake gcc lcov libevent-dev libglib2.0-dev libgmime-2.6-dev libluajit-5.1-dev liblua5.1-0-dev libmagic-dev libpcre3-dev libsqlite3-dev libssl-dev make python-dev ragel redis-server
       - gem install coveralls-lcov
       - sudo pip install demjson psutil robotframework
+      - wget http://download.redis.io/redis-stable.tar.gz
+      - tar xvzf redis-stable.tar.gz
+      - cd redis-stable
+      - make
+      - sudo cp src/redis-cli /usr/bin/
 
 test:
   override: