Load YAML safely
Load YAML safely

The default `yaml.load()` can execute arbitrary code from a file, which is generally not what you want when opening a document. `safe_load()` is ~always what you want when reading YAML.

See the warning [in the PyYAML docs](http://pyyaml.org/wiki/PyYAMLDocumentation#LoadingYAML). Even if all of the examples following the warning use the unsafe functions anyway :angry:.
prabhuramachandran/ipyaml