Added podspec
modified:   AAShareBubbles/AAShareBubbles.h
modified:   AAShareBubbles/AAShareBubbles.m
new file:   AAShareBubbles/icon-aa-linkedin.png
new file:   AAShareBubbles/icon-aa-linkedin@2x.png
modified:   Demo/AAShareBubbles/ViewController.m

Added LinkedIn (Proffessional social network)