[ANN] packetgen 1.4.1 released

packetgen 1.4.1 has been released.

* home: <https://github.com/sdaubert/packetgen>
* bugs: <https://github.com/sdaubert/packetgen/issues>
* doc: <http://www.rubydoc.info/gems/packetgen>

PacketGen provides simple ways to generate, send and capture network
packets.

Known protocols are: Ethernet, Dot11, Dot1x, IP, IPv6, ARP, ICMP,
ICMPv6, UDP, TCP, ESP and DNS.

Changes:

### 1.4.1 / 2017-03-11

* PacketGen::Capture.new: iface argument is no more mandatory. If
undefined, select first network interface.
* add an interactive console with pgconsole executable