Slippy Map Tile conversion bug

[gopi-ar]

There's a PHP issue while converting from lat back to tile as documented here. This will need fixing here:

mbtiles-generator/src/HTML24/MBTilesGenerator/Util/Calculator.php

Line 41 in 6dcb5dc

(1 - log(tan(deg2rad($latitude)) + 1 / cos(deg2rad($latitude))) / pi()) / 2 * pow(2, $zoom)