Look into compressing PNGs wtih PNGQuant

[davidrans]

Having the option to compress PNGs would be cool: https://pngquant.org/

[djmetzle]

Is this not working correctly?

charge/lib/charge/services/image_converter.rb

Lines 57 to 60 in 5a47e1d

	def optimize_png output_file
	png_file_path = output_file.path
	puts "Running png optimization..."
	cmd = "pngquant --force --strip #{png_file_path.shellescape} --out #{png_file_path.shellescape}"