Update README.md (#17)

Author: billiegoose

README.md

@@ -49,6 +49,8 @@ import FS from '@isomorphic-git/lightning-fs';
 const fs = new FS("testfs")
 ```
 
+**Note: do not create multiple `fs` instances using the same name.** If you do, you'll have two distinct FileSystems both fighting over the same IndexedDb store.
+
 Options object:
 
 | Param  | Type [= default]   | Description                                                           |
@@ -147,4 +149,4 @@ All the same functions as above, but instead of passing a callback they return a
 
 ## License
 
-MIT
+MIT

karma.conf.js

@@ -79,15 +79,15 @@ module.exports = function (config) {
         platformName: 'iOS',
         platformVersion: '11.2',
         browserName: 'Safari',
-        appiumVersion: '1.7.2'
+        appiumVersion: '1.9.1'
       },
       sl_android_chrome: {
         base: 'SauceLabs',
         deviceName: 'Android GoogleAPI Emulator',
         platformName: 'Android',
         platformVersion: '7.1',
         browserName: 'Chrome',
-        appiumVersion: '1.7.2'
+        appiumVersion: '1.9.1'
       },
       FirefoxHeadless: {
         base: 'Firefox',