push notification to many devices support

support for sending push notification to many devices via Gcm.
Push notification to many installations

Add notifyMany method for sending notification to many devices for given appId, device type and array of device tokens.
Add fixes to notifyMany and tests.

Signed-off-by: Aris Kemper <aris.github@gmail.com>
Fix gcm pushNotification and add test case for array of device tokens.
Fix gcm pushNotification and add test case for array of device tokens. Signed-off-by: Aris Kemper <aris.github@gmail.com>
Fix gcm pushNotification and add test case for array of device tokens. Signed-off-by: Aris Kemper <aris.github@gmail.com>
Merge tag 'v1.2.3'

1.2.3
Upgrade to apn version 1.6.0.

Upgraded to apn version 1.6.0, which fixes several issues with socket.

+1.6.0:
 +
 +* Fixes #156: Retire a socket from the pool immediately instead of waiting for a "close" event.
 +* Fixes #165: Introduced a connection retry limit to emit errors when fatal connection errors occur.
 +* Fixes #152: Failure to attach an error handler would prevent exponential backoff from working.
 +* Improved error handling for EPIPE write events to maximise chances of reading error info from Apple.
 +* Fixed #181: Initial support for larger payloads for iOS 8 testing.
 +* Fixed #187: Correctly trim notifications with escaped characters.
 +* Merged #190: Always emit a feedback event when batch mode is enabled, even if there are no tokens. 
 +* Merged #189: Added support for iOS 8 Notification actions.
 +* Display a warning when null parameters are passed during connection creation.
 +* Fixed #171: Removed references to the unknown notification identifier.

Signed-off-by: Aris Kemper <aris.github@gmail.com>
Merge pull request #43 from ariskemper/patch-4

Upgrade to apn version 1.6.0.
Bump version
Ensure deviceType/token are populated from installation
Merge pull request #44 from strongloop/feature/fix-notify

Ensure deviceType/token are populated from installation
Merge pull request #42 from ariskemper/patch-3

Push notification to many installations
Merge pull request #41 from ariskemper/patch-2

GCM push notification support many device tokens
Bump version
Merge branch 'release/1.3.0' into production