* Update tests to include missing `token` property to a Tx of Ether or Token

* Update tests to include missing `address` property to a Tx of Ether to fixes `TypeError: Cannot read property 'address' of undefined` error

* Update tests to include missing `options` and `args` properties to the Tx so the second argument passed to `transfer$` in `contractForToken(token.address).transfer$(..., ...)` is not NaN

* Fix error `ReferenceError: regeneratorRuntime is not defined`

* Fixes `SyntaxError ... Decorators transform is necessary.` (regarding use of `@observable`)
* Fixes `Decorating class property failed. Please ensure that proposal-class-properties is enabled and set to use loose mode. To use proposal-class-properties in spec mode with decorators, wait for the next major version of decorators in stage 2.`

Fixes error: 'pipelineOperator' requires 'proposal' option whose value should be one of: 'minimal', 'smart'

Reference: https://www.electron.build/icons#windows-nsis