Rakefile | 4 2 2 - 0 !
1 file changed, 2 insertions( ), 2 deletions(-)

 disable rubygems and bundler usage

lib/psych/versions.rb | 2 1 1 - 0 !
1 file changed, 1 insertion( ), 1 deletion(-)

 remove snakeyaml hardcoded versions

Rakefile | 13 10 3 - 0 !
1 file changed, 10 insertions( ), 3 deletions(-)

 disable ruby-maven

lib/psych/visitors/yaml_tree.rb | 4 2 2 - 0 !
test/psych/test_psych.rb | 7 5 2 - 0 !
2 files changed, 7 insertions( ), 4 deletions(-)

 fix restrictedyamltree allowing the symbol class should allow all
 symbols

Ref: https://github.com/ruby/psych/pull/495

That's how it works for `safe_load`:
```ruby
>> YAML.safe_load(':foo', permitted_classes: [Symbol])
=> :foo
```

So `safe_dump` should mirror that.