Release v0.5.7

• 42492c8 chore(release): 0.5.7
• c1e05ff docs(readme): Fix markdown table alignment
• a6dbfb0 build: Push tag before branch after a release
• 9db3c44 cleanup: Remove comments
• 1f925d4 doc(html): Add doc for Eval/Run methods
• d7dca66 fix(v8): Node.insertBefore failed on missing ref
• e02ac4a test: Migrate node tests to testify suite
• 1fede2f test: Make script host suite members public
• c5eae12 test: HaveTextContent checks for nil