0.2.0-beta.1

• [Changed] Behavior changed in major APIs (.query(), .call() and .checkTx()). (#18)
• [New] Add .ua.isWalletMobileApp() API. (b2f9fc0)
• [Fixed] Fix an uncaught exception on startup. (bd9684f)
• [Improved] Upgrade built-in nebPay to v0.2.1.
• [Improved] Adapt .ua.isWalletExtensionInstalled() API to NasExtWallet v0.1.3+. (#17)
• [Improved] Through error if fail to register payId to server in .call() API. (#17)
• [Improved] Add built-in web server to run demo page. (#25)
• [Improved] Reorganize code and API namespace. (#16)

Unstable experimental features:

• [New] Add options.from param for .query() API. (#27)
• [New] Add .config() API to specify Nebulas API endpoint. (#27)