v0.3.1

• Added: opts.keychain to limit and to find identity for signing.
• Added: opts.ignore of electron-osx-sign to verify whether file to be signed.
• Changed: Array.indexOf instead of Array.includes for better compatibility.
• Changed: Binary files, including native node addons are now automatically signed.
• Changed: node_modules no longer skipped.
• Changed: Now uses external module debug to display logs and messages, need export DEBUG=electron-osx-sign*.
• Deprecated: opts.verbose.