Add additional options to control BrowserStackLocal binary (#78)

* Allow setting the logfile via BROWSERSTACK_LOGFILE environment variable

* Allow setting the verbosity via BROWSERSTACK_VERBOSE environment variable

* Allow setting BrowserStackLocal binary path via BROWSERSTACK_BINARY_PATH

* Document the new options in the README

* [docs] Add an example for BrowserStackLocal options

README.md

@@ -59,6 +59,24 @@ export BROWSERSTACK_FORCE_LOCAL="1"
 testcafe browserstack:chrome test.js
 ```
 
+## Other BrowserStackLocal Options
+
+This plugin also allows you to specify the following [BrowserStackLocal](https://github.com/browserstack/browserstack-local-nodejs) options via environment variables:
+
+Option  | Environment Variable
+------  | --------------------
+[binarypath](https://github.com/browserstack/browserstack-local-nodejs#binary-path) | `BROWSERSTACK_BINARY_PATH`
+[logFile](https://github.com/browserstack/browserstack-local-nodejs#logfile) | `BROWSERSTACK_LOGFILE`
+[verbose](https://github.com/browserstack/browserstack-local-nodejs#verbose-logging) | `BROWSERSTACK_VERBOSE`
+
+Example:
+```
+export BROWSERSTACK_BINARY_PATH="~/BrowserStack/BrowserStackLocal"
+export BROWSERSTACK_LOGFILE="~/BrowserStack/logs.txt"
+export BROWSERSTACK_VERBOSE="1"
+testcafe browserstack:chrome test.js
+```
+
 ## Browserstack JS Testing and Browserstack Automate
 Browserstack offers two APIs for browser testing:
  - [Browserstack JS Testing](https://www.browserstack.com/javascript-testing-api)

src/connector.js

@@ -58,16 +58,20 @@ export default class BrowserstackConnector {
         return new Promise((resolve, reject) => {
             var connector    = new BrowserstackLocal();
             var parallelRuns = process.env['BROWSERSTACK_PARALLEL_RUNS'];
-
+            var logfile = process.env['BROWSERSTACK_LOGFILE'] || (OS.win ? this._getTempFileName() : '/dev/null');
+            var verbose = process.env['BROWSERSTACK_VERBOSE'];
+            var binarypath = process.env['BROWSERSTACK_BINARY_PATH'];
 
             var opts = {
                 key:             this.accessKey,
-                logfile:         OS.win ? this._getTempFileName() : '/dev/null',
+                logfile,
                 forceLocal:      !!process.env['BROWSERSTACK_FORCE_LOCAL'],
                 forceProxy:      !!process.env['BROWSERSTACK_FORCE_PROXY'],
                 localIdentifier: Date.now(),
 
                 ...parallelRuns ? { parallelRuns } : {},
+                ...verbose ? { verbose } : {},
+                ...binarypath ? { binarypath } : {},
 
                 //NOTE: additional args use different format
                 'enable-logging-for-api': true