Version bump: 0.9.0 (ethereum#2716)

* Adding recommended node version used by Electron

* Version bump

* updating yarn.lock

.nvmrc

@@ -0,0 +1 @@
+7.4

package.json

@@ -1,6 +1,6 @@
 {
   "name": "Mist",
-  "version": "0.8.10",
+  "version": "0.9.0",
   "license": "GPL-3.0",
   "author": "Ethereum Mist Team <[email protected]>",
   "repository": {
@@ -45,7 +45,7 @@
     "co-mocha": "^1.2.0",
     "del": "^2.2.2",
     "ecstatic": "^2.1.0",
-    "electron": "1.6.2",
+    "electron": "1.4.15",
     "electron-builder": "^12.2.2",
     "eslint": "^3.14.1",
     "eslint-config-airbnb-base": "^11.0.1",

yarn.lock

@@ -996,9 +996,9 @@ electron-window-state@^4.0.1:
     jsonfile "^2.2.3"
     mkdirp "^0.5.1"
 
-electron@1.6.2:
-  version "1.6.2"
-  resolved "https://registry.yarnpkg.com/electron/-/electron-1.6.2.tgz#b0ccd7703f86d09c4d2a7273455c3f993f158994"
+electron@1.4.15:
+  version "1.4.15"
+  resolved "https://registry.yarnpkg.com/electron/-/electron-1.4.15.tgz#eaccafe3f55ade02a746b706ac14b43db6c7ccf8"
   dependencies:
     electron-download "^3.0.1"
     extract-zip "^1.0.3"