v20180517

• Show account balance, refs #8
• Configurable gas price, refs #23
• UI improvements, refs #34, #88
• File split & refactoring, refs #43
• Lazy screen loading, refs #47, #75
• Pull to refresh roll history, refs #50, #55
• Updated contract deployment doc, refs #52
• UI testing, refs #61, #64
• Reduce APK size from 26M to 20M, refs #68
• Run tests from UI, refs #69
• Ubuntu Bionic 18.04 support, refs #70, #71
• Show changelog from the app, refs #73
• Fix scrypt support, refs #76
• Fix ETH to wei conversion, refs #77
• Fix test timestamp overflow, refs #78
• Fix history error on no matching tx, refs #87