According to a source, Tesla will start construction of a new facility in Shanghai next month, reiterating Elon Musk's vow to double electric vehicle production in China, The New York Post reported.According to the report, the facility will be constructed near Tesla's present factory in Lingang, known as Gigafactory 3. The company's expanded footprint in Shanghai can reportedly be attributed to the city's friendly business climate. Unlike other international automakers, Shanghai has exempted Tesla from forming a joint venture with a domestic automaker, allowing Musk's company to control the entire manufacturing facility. Tesla's sales in China have soared, and the…