Fix missing variable and unique local identifiers

Author: sinstein

lib/browserstack/local.rb

@@ -135,7 +135,7 @@ def start_command
 
   def start_command_args
     args = [@binary_path, "-d", "start", "-logFile", @logfile, @key, @folder_flag, @folder_path, @force_local_flag]
-    args += ["-localIdentifier", local_identifier_flag] if @local_identifier_flag
+    args += ["-localIdentifier", @local_identifier_flag] if @local_identifier_flag
     args += [@only_flag, @only_automate_flag]
     args += ["-proxyHost", @proxy_host] if @proxy_host
     args += ["-proxyPort", @proxy_port] if @proxy_port

test/browserstack-local-test.rb

@@ -1,4 +1,5 @@
 require 'rubygems'
+require 'securerandom'
 require 'minitest'
 require 'minitest/autorun'
 require 'browserstack/local'
@@ -9,12 +10,12 @@ def setup
   end
 
   def test_check_pid
-    @bs_local.start
+    @bs_local.start({"localIdentifier" => SecureRandom.hex})
     refute_nil @bs_local.pid, 0
   end
 
   def test_is_running
-    @bs_local.start
+    @bs_local.start({"localIdentifier" => SecureRandom.hex})
     assert_equal true, @bs_local.isRunning
   end