Fix sed command in travis ci

.travis.yml

@@ -9,7 +9,7 @@ env:
 
 before_script:
   - cat /etc/mysql/my.cnf | grep -i 'bind-address'
-  - sudo sed 's/^bind-address.*\/bind-address = 0.0.0.0/’ /etc/mysql/my.cnf
+  - sudo sed -i 's/^bind-address.*/bind-address = "0.0.0.0"/' /etc/mysql/my.cnf
   - cat /etc/mysql/my.cnf | grep -i 'bind-address'
   - sudo curl -L https://github.com/docker/compose/releases/download/1.22.0/docker-compose-$(uname -s)-$(uname -m) -o /usr/local/bin/docker-compose
   - |