Paul Singer’s activist hedge fund Elliott Management has ramped up pressure on $2 billion software company CDK Global, penning a new letter to the company’s leadership outlining the “significant opportunity” in front of CDK and steps it believes are crucial in realizing it.  Elliott initially disclosed a stake in CDK last May and owns 8.6% of the company’s outstanding stock, making it one of the firm’s largest shareholders and one of three activist hedge funds in the firm. CDK was spun out of Automatic Data Processing in 2014 and, in the face of a steep decline in its stock price...