解决办法：composer install

Problem 1
    - laravelista/ekko 1.4.0 requires php >=5.6.0 -> your PHP version (5.5.38) does not satisfy that requirement.
    - laravelista/ekko 1.3.3 requires php >=5.6.0 -> your PHP version (5.5.38) does not satisfy that requirement.

php版本不匹配，接着

composer install --ignore-platform-reqs 忽略版本匹配