fix: changed lt(exclusiveMaximum) to le(maximum) for DEM algorithms

[JinIgarashi]

@vincentsarago I am sorry, I did a mistake for maximum value setting for DEM algorithms. It should be le (maximum) instead of lt (exclusiveMaximum).

I fixed them, and the new response of /algorithms endpoint is shown below

/algorithms endpoint response

```json { "hillshade":{ "title":"Hillshade", "description":"Create hillshade from DEM dataset.", "inputs":{ "nbands":1 }, "outputs":{ "nbands":1, "dtype":"uint8", "min":null, "max":null }, "parameters":{ "azimuth":{ "default":90, "maximum":360, "minimum":0, "title":"Azimuth", "type":"integer" }, "angle_altitude":{ "default":90, "maximum":90, "minimum":-90, "title":"Angle Altitude", "type":"number" }, "buffer":{ "default":3, "maximum":99, "minimum":0, "title":"Buffer", "type":"integer" } } }, "contours":{ "title":"Contours", "description":"Create contours from DEM dataset.", "inputs":{ "nbands":1 }, "outputs":{ "nbands":3, "dtype":"uint8", "min":null, "max":null }, "parameters":{ "increment":{ "default":35, "maximum":999, "minimum":0, "title":"Increment", "type":"integer" }, "thickness":{ "default":1, "maximum":10, "minimum":0, "title":"Thickness", "type":"integer" }, "minz":{ "default":-12000, "maximum":99999, "minimum":-99999, "title":"Minz", "type":"integer" }, "maxz":{ "default":8000, "maximum":99999, "minimum":-99999, "title":"Maxz", "type":"integer" } } }, "normalizedIndex":{ "title":"Normalized Difference Index", "description":"Compute normalized difference index from two bands.", "inputs":{ "nbands":2 }, "outputs":{ "nbands":1, "dtype":"float32", "min":[ -1 ], "max":[ 1 ] }, "parameters":{ } }, "terrarium":{ "title":"Terrarium", "description":"Encode DEM into RGB (Mapzen Terrarium).", "inputs":{ "nbands":1 }, "outputs":{ "nbands":3, "dtype":"uint8", "min":null, "max":null }, "parameters":{ } }, "terrainrgb":{ "title":"Terrarium", "description":"Encode DEM into RGB (Mapbox Terrain RGB).", "inputs":{ "nbands":1 }, "outputs":{ "nbands":3, "dtype":"uint8", "min":null, "max":null }, "parameters":{ "interval":{ "default":0.1, "maximum":1, "minimum":0, "title":"Interval", "type":"number" }, "baseval":{ "default":-10000, "maximum":99999, "minimum":-99999, "title":"Baseval", "type":"number" } } } } ```