Move subscription to constructor (#9)

* dev

* fix version

Author: nulldef

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@umbrellio/observable",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "Observable library",
   "repository": "git@github.com:umbrellio/observable.git",
   "author": "Aleksei Bespalov <nulldefiner@gmail.com>",

src/observer.js

@@ -6,7 +6,8 @@ const observer = (store, { key, map }) => WrappedComponent => {
 
     state = { ...store.getState() }
 
-    componentDidMount () {
+    constructor (props) {
+      super(props)
       this.unsubscribe = store.subscribe(data => this.setState(data))
     }