[ImgBot] optimizes images

\public\images\icon-mock.png (11.91%))
\public\images\icon.png (52.7%))
\public\images\logo.png (10.53%))
\public\images\icon-swagger.png (11.42%))
\public\images\icon-command.png (31.44%))
\public\images\group-default.png (1.63%))
\views\pages\docs\images\response.png (22.47%))
\public\images\easy-mock.png (29.02%))
\views\pages\docs\images\qq-qun.jpg (30%))
\views\pages\docs\images\petstore.png (14.6%))
\views\pages\docs\images\create-project.png (16.79%))
\views\pages\docs\images\create-mock.png (10.63%))
\views\pages\docs\images\preview.png (15.32%))
\views\pages\docs\images\demo.png (12.31%))