Error

[sterichards]

Installing svp1989/symfony-api-skeleton (dev-master 1975469)

• Installing svp1989/symfony-api-skeleton (dev-master 1975469): Cloning 1975469 from cache
  Created project in fillform
  Loading composer repositories with package information
  Installing dependencies (including require-dev) from lock file
  Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. Run update to update them.
  Your requirements could not be resolved to an installable set of packages.

Problem 1
- Installation request for symfony/security v3.4.7 -> satisfiable by symfony/security[v3.4.7].
- don't install symfony/security-core v4.0.7|don't install symfony/security v3.4.7
- Installation request for symfony/security-core v4.0.7 -> satisfiable by symfony/security-core[v4.0.7]