fix(isolate): fix typings for isolate, accepts any sources
fix(isolate): fix typings for isolate, accepts any sources

Previously, isolate() in TypeScript was generic, parameterized by Sources and Sinks, but the Sources
had to follow a certain restrictive shape. With this change, the restriction is dropped, and the
sources can be any type. isolate() has weak typings since TypeScript does not provide the inference
capabilities we need.

cyclejs/cyclejs,cyclejs/cycle-core,staltz/cycle,feliciousx-open-source/cyclejs,usm4n/cyclejs,feliciousx-open-source/cyclejs,cyclejs/cyclejs,ntilwalli/cyclejs,maskinoshita/cyclejs,ntilwalli/cyclejs,usm4n/cyclejs,cyclejs/cycle-core,usm4n/cyclejs,maskinoshita/cyclejs,feliciousx-open-source/cyclejs,cyclejs/cyclejs,staltz/cycle,usm4n/cyclejs,ntilwalli/cyclejs,maskinoshita/cyclejs,maskinoshita/cyclejs,cyclejs/cyclejs,feliciousx-open-source/cyclejs,ntilwalli/cyclejs