This includes updates for resolving all warnings provided by Ruby
for deprecations and/or removed methods. It also enables support
for Ruby 2.7 in the specification constraint as all 2.7 related
warnings are resolved with this changeset.
Prior to this commit, if a user had recently checked for updates, there
was no way to force Vagrant to re-check without manually deleting a
state file in the local `.vagrant` data dir. This commit fixes that by
giving users the ability to force check for updates for a given box with
a flag to the `vagrant box outdated` command.
This commit changes the behavior of `vagrant box outdated --global` so
it gets the latest version for the current machine's provider, rather
than the latest version for any provider.