Make heat_map module public to expose Smoothing enum.

plotly/src/lib.rs

@@ -30,7 +30,9 @@ pub use configuration::Configuration;
 pub use layout::Layout;
 pub use plot::{ImageFormat, Plot, Trace};
 // Also provide easy access to modules which contain additional trace-specific types
-pub use traces::{box_plot, contour, histogram, image, mesh3d, sankey, scatter_mapbox, surface};
+pub use traces::{
+    box_plot, contour, heat_map, histogram, image, mesh3d, sankey, scatter_mapbox, surface,
+};
 // Bring the different trace types into the top-level scope
 pub use traces::{
     Bar, BoxPlot, Candlestick, Contour, DensityMapbox, HeatMap, Histogram, Image, Mesh3D, Ohlc,

plotly/src/traces/mod.rs

@@ -5,7 +5,7 @@ pub mod box_plot;
 mod candlestick;
 pub mod contour;
 mod density_mapbox;
-mod heat_map;
+pub mod heat_map;
 pub mod histogram;
 pub mod image;
 pub mod mesh3d;