fix: Problems downloading electron electron-userland#180

Closes electron-userland#180

src/util.ts

@@ -99,7 +99,9 @@ export async function getElectronVersion(packageData: any, packageJsonPath: stri
     return (await readJson(path.join(path.dirname(packageJsonPath), "node_modules", "electron-prebuilt", "package.json"))).version
   }
   catch (e) {
-    // ignore
+    if (e.code !== "ENOENT") {
+      console.warn("Cannot read electron version from electron-prebuilt package.json" + e.message)
+    }
   }
 
   const devDependencies = packageData.devDependencies

test/src/BuildTest.ts

@@ -1,6 +1,6 @@
 import test from "./helpers/avaEx"
 import { assertPack, modifyPackageJson, platform } from "./helpers/packTester"
-import { move, mkdirs, outputFile } from "fs-extra-p"
+import { move, mkdirs, outputFile, outputJson } from "fs-extra-p"
 import { Promise as BluebirdPromise } from "bluebird"
 import * as path from "path"
 import { assertThat } from "./helpers/fileAssert"
@@ -53,6 +53,23 @@ test("build in the app package.json", t => {
   }), /'build' in the application package\.json .+/)
 })
 
+test("version from electron-prebuilt dependency", async () => {
+  await assertPack("test-app-one", {
+    platform: [process.platform],
+    arch: process.arch,
+    dist: false
+  }, projectDir => {
+    return BluebirdPromise.all([
+      outputJson(path.join(projectDir, "node_modules", "electron-prebuilt", "package.json"), {
+        version: "0.37.2"
+      }),
+      modifyPackageJson(projectDir, data => {
+        data.devDependencies = {}
+      })
+    ])
+  })
+})
+
 test("copy extra resource", async () => {
   const platform = process.platform
   const osName = Platform.fromNodePlatform(platform).buildConfigurationKey