fix: stopbits definition and move binding-mock (#2419)

- fix stopbits definition to 1 | 1.5 | 2
- This also includes moving binding-mock to it's own repo for details on why this has to be done at the same time see serialport/binding-mock#2

Author: reconbot

package-lock.json

@@ -25,7 +25,7 @@
     "url": "git://github.com/serialport/node-serialport.git"
   },
   "devDependencies": {
-    "@serialport/bindings-cpp": "^10.6.1",
+    "@serialport/bindings-cpp": "^10.6.2",
     "@tsconfig/node12": "^1.0.9",
     "@types/chai": "^4.3.0",
     "@types/chai-subset": "^1.3.3",

package.json

@@ -1,6 +1,3 @@
 # @serialport/binding-mock
 
-```ts
-import { MockBinding } from '@serialport/binding-mock'
-const MockBinding = new MockBinding()
-```
+The code for this package has been moved out of the monorepo to it's [own repository](https://github.com/serialport/binding-mock/).