saucelabs: default evergreen browsers to latest version; test iOS for 7.1

Author: yyx990803

build/saucelabs-config.js

@@ -16,19 +16,16 @@ var batches = [
     sl_chrome: {
       base: 'SauceLabs',
       browserName: 'chrome',
-      platform: 'Windows 7',
-      version: '39'
+      platform: 'Windows 7'
     },
     sl_firefox: {
       base: 'SauceLabs',
-      browserName: 'firefox',
-      version: '33'
+      browserName: 'firefox'
     },
     sl_mac_safari: {
       base: 'SauceLabs',
       browserName: "safari",
-      platform: "OS X 10.10",
-      version: "8"
+      platform: "OS X 10.10"
     }
   },
   // ie family
@@ -58,7 +55,7 @@ var batches = [
       base: 'SauceLabs',
       browserName: 'iphone',
       platform: 'OS X 10.9',
-      version: '8.1'
+      version: '7.1'
     },
     sl_android: {
       base: 'SauceLabs',
@@ -79,4 +76,4 @@ for (var i = 0; i < 3; i++) {
     browsers: Object.keys(batches[i]),
     reporters: ['progress', 'saucelabs']
   }
-}
+}