http://techcrunch.com – The number of startup accelerators has grown exponentially over the last few years. There are now over 100 of them scattered throughout the U.S. — a fairly dramatic increase from 2007, when there were just about four, according to Y Combinator’s estimates. Today, when it seems that every vertical — mobile, gaming, hardware, etc. — has its own accelerator, education remains somewhat of an outlier. That’s why, after encouragement from YC founder Paul Graham, former Yahoo and Google execs Tim Brady, Alan Louie and Geoff Ralston created Imagine K12 in 2011 — to (IT news)