Slice, an Indian fintech startup that has built a “super card” for millennials in India, said on Monday it has raised $20 million in a new financing round and is adding new features to change how people engage with their credit cards. Existing investors Gunosy, Blume Ventures and others financed the new round in the Bangalore-headquartered startup, it said. Even as hundreds of millions of Indians today have a bank account, only about 30 million have a credit card. Most people in the South Asian market are not eligible to…