Added initialAngle to Pie charts and fixed issue with barMarginBottom

docs/PieChart/PieChartProps.md

@@ -4,6 +4,7 @@
 | -------------------- | -------------- | --------------------------------------------------------------------------------------------------------- | --------------- |
 | data                 | Array of items | An item object represents a section in the Pie chart. Descibed in the next table                          | \_              |
 | radius               | number         | Radius of the Pie chart                                                                                   | 120             |
+| initialAngle         | number         | Starting angle in radians (illustrated below this table)                                                  | 0               |
 | isThreeD             | Boolean        | If set to true, it rotates and translates the chart to give it a 3D effect                                | false           |
 | shadow               | Boolean        | Shadow to the Pie chart, when set to true, it enhances the 3D effect                                      | false           |
 | shadowColor          | ColorValue     | Color of the shadow                                                                                       | lightgray       |
@@ -24,6 +25,11 @@
 | centerLabelComponent | Function       | Component to be rendered at the center of the Pie chart                                                   | \_              |
 | semiCircle           | Boolean        | When set to true, renders the Pie Chart in a semi-circle. donut semiCircle charts look like a speed-meter | false           |
 
+#### initialAngle
+
+The default value is 0. The angles are distributed differently from the usual coordinate system. It is illustrated below-
+<img src='../../demos/pie.png' alt='' height=400 width=400/>
+
 ### Item description
 
 | Prop                 | Type       | Description                                                            |

src/BarChart/RenderBars.tsx

@@ -111,7 +111,9 @@ const RenderBars = (props: Props) => {
   } = props;
 
   const barMarginBottom =
-    item.barMarginBottom === 0 ? 0 : props.barMarginBottom || 0;
+    item.barMarginBottom === 0
+      ? 0
+      : item.barMarginBottom || props.barMarginBottom || 0;
 
   const renderLabel = (label: String, labelTextStyle: any, value: number) => {
     return (

src/PieChart/index.tsx

@@ -34,6 +34,7 @@ type propTypes = {
 
   centerLabelComponent?: Function;
   tilt?: number;
+  initialAngle?: number;
 };
 type itemType = {
   value: number;
@@ -96,6 +97,7 @@ export const PieChart = (props: propTypes) => {
     '800',
     '900',
   ];
+  const initialAngle = props.initialAngle || 0;
 
   let isDataShifted = false;
   data.forEach((item: any) => {
@@ -148,7 +150,7 @@ export const PieChart = (props: propTypes) => {
     /******************************************************/
 
     let i = 0,
-      angleSum = 0;
+      angleSum = initialAngle;
     let colors = [
       'cyan',
       'green',