Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires wyrihaximus/react-awaitable-observable dev-3283c1af134db0caa156a912e00a06ee4e8737bf -> satisfiable by wyrihaximus/react-awaitable-observable[dev-3283c1af134db0caa156a912e00a06ee4e8737bf]. - wyrihaximus/react-awaitable-observable dev-3283c1af134db0caa156a912e00a06ee4e8737bf requires reactivex/rxphp dev-template-types as 2.0.13 -> found reactivex/rxphp[dev-master, 0.1.0, 0.2.0, 0.2.1, 0.3.0, 0.4.0, 0.5.0, 1.0.0, 1.1.0, 1.2.0, 1.3.0, 1.4.0, 1.4.1, 1.5.0, 1.5.1, 1.5.2, 1.5.3, 1.x-dev, 2.0.0, 2.0.1, 2.0.2, 2.0.3, 2.0.4, 2.0.5, 2.0.6, 2.0.7, 2.0.8, 2.0.9, 2.0.10, 2.0.11, 2.0.12, 2.0.x-dev (alias of dev-master), 2.x-dev] but it does not match the constraint.

Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires wyrihaximus/react-awaitable-observable dev-65/merge, found wyrihaximus/react-awaitable-observable[dev-3283c1af134db0caa156a912e00a06ee4e8737bf] but it does not match the constraint.