fix(overmind): bind correctly proxifying effects

Author: christianalfoni

packages/node_modules/overmind/src/proxyfyEffects.ts

@@ -12,7 +12,7 @@ function wrapEffect(target, prop, path, cb) {
     const effectId = currentEffectId++
 
     return cb({
-      func: target[prop],
+      func: target[prop].bind(target),
       effectId,
       name: path,
       method: prop,