Update dependencies for phpdocumentor/reflection

[kkmuffme]

"phpdocumentor/reflection" : "~3.0",

but latest version is https://github.com/phpDocumentor/Reflection 5.1.0

Due to this, this package cannot be used anymore in most installs, as there are dependency conflicts.

[iandunn]

There's also a conflict with wp-cli-psysh, and the wp-cli 2.7.0-alpha source version. wp-cli 2.6.0 binary works fine though.

[iandunn]

Related #211