Don't set default height

This will fix chart height not overridable by global/default options

lib/apex_charts/options_builder.rb

@@ -83,7 +83,7 @@ def build_chart
       built[:chart].merge!({
         id: @options[:chartId] || @options[:id],
         group: @options.delete(:group),
-        height: @options.delete(:height) { target ? 180 : 400 },
+        height: @options.delete(:height) { target ? 180 : nil },
         width: @options.delete(:width),
         stacked: @options.delete(:stacked),
         animations: enabled(@options.delete(:animations)),

lib/apex_charts/renderer.rb

@@ -89,11 +89,14 @@ def css_class
     end
 
     def height
-      "#{options[:chart][:height].to_i}px"
+      chart_height = options.dig(:chart, :height)
+      if chart_height
+        "#{chart_height.to_i}px"
+      end
     end
 
     def style
-      "height: #{height}; #{attributes.delete(:style)}"
+      "#{height && "height: #{height}; "}#{attributes.delete(:style)}"
     end
 
     def window_apex

spec/charts/mixed_charts_spec.rb

@@ -44,9 +44,7 @@
     expect(chart.more_options).to eq({})
     expect(chart.instance_variable_get(:@series)).to eq(expected_series)
     expect(chart.instance_variable_get(:@options)).to eq(
-      chart: {
-        height: 400, id: 'chart-1', type: 'area'
-      },
+      chart: {id: 'chart-1', type: 'area'},
       defer: false,
       div: {id: 'chart-1'},
       module: false,