`json-rules-engine-simplified` is a necessary dependency

[ivarprudnikov]

Issue: Using react-jsonschema-form-conditionals alone with json-rules-engine fails to resolve dependency of json-rules-engine-simplified.

Expected behavior: react-jsonschema-form-conditionals and usage of json-rules-engine should not produce dependency issue.

Cause: utils.js depends on json-rules-engine-simplified/lib/utils

Suggestion: Move json-rules-engine-simplified dependency out of devDependencies into dependencies block in package.json.