On OSX the plugin always fails to connect to the started emulator.
Affected since version 2.13.
It is working in version 2.12.

[android] Starting Android emulator
$ /usr/local/opt/android-sdk/tools/emulator64-arm -no-boot-anim -ports 49759,49760 -prop persist.sys.language=de -prop persist.sys.country=DE -avd hudson_de-DE_160_HVGA_android-18_armeabi-v7a -no-snapshot-load -no-snapshot-save -wipe-data

• daemon not running. starting it now on port 49761 *
• daemon started successfully *
  emulator: UpdateCheck: current version '24.4.1', last version '24.4.1'
  $ /usr/local/opt/android-sdk/platform-tools/adb connect localhost:49760
  [android] Waiting for emulator to finish booting...
  $ /usr/local/opt/android-sdk/platform-tools/adb -s localhost:49760 shell getprop dev.bootcomplete
  error: device 'localhost:49760' not found
  $ /usr/local/opt/android-sdk/platform-tools/adb connect localhost:49760
  $ /usr/local/opt/android-sdk/platform-tools/adb -s localhost:49760 shell getprop dev.bootcomplete
  error: device 'localhost:49760' not found
  ....
  $ /usr/local/opt/android-sdk/platform-tools/adb connect localhost:49760
  [android] Timed-out after waiting 720 seconds for emulator
  $ /usr/local/opt/android-sdk/platform-tools/adb disconnect localhost:49760
  error: no such device 'localhost:49760'
  [android] Stopping Android emulator
  $ /usr/local/opt/android-sdk/platform-tools/adb kill-server