title: How to give gradient color to topBar wix's react-native-navigation V2
body: <p>I am using Wix's react-native-navigation V2. I want to give gradient color to the topBar. I have installed react-native-linear-gradient successfully. But I am not getting how to give gradient color to topBar.</p>
  
  <p>Following is the code of pushing the screen into the stack.</p>
  
  <pre><code>Navigation.push('mainStack', {
        component: {
          name: 'SignIn',
          options: {
            topBar: {
              visible: true,
              animate: false,
              //hideOnScroll: true,
              //buttonColor: 'white',
              drawBehind: false,
              title: {
                text: 'Sign In',
                fontSize: 18,
                //color: 'white',
                fontFamily: 'Ubuntu',
                alignment: 'center'
              },
              backButton: {
                // icon: require('icon.png'),
                id: 'backButton',
                visible: true,
                //color: 'white'
              },
              background: {
                color: '#1abc9c'
              }
            },
            sideMenu: {
              left: {
                enabled: false
              }
            },
            animations: {
              push: { // It works! Push with animation from right to left
                content: {
                  x: {
                    from: 1000,
                    to: 0,
                    duration: 100,
                  },
                  alpha: {
                    from: 1,
                    to: 1,
                    duration: 100,
                  }
                }
              },
              pop: { // It works! Pop with animation from left to right
                content: {
                  x: {
                    from: 0,
                    to: 1000,
                    duration: 50,
                  },
                  alpha: {
                    from: 1,
                    to: 1,
                    duration: 50,
                  }
                }
              }
            }
          }
        }
      });
  </code></pre>
  
  <p>I tried to give a gradient color in options like below</p>
  
  <pre><code>background: {
                color: &lt;LinearGradient colors={['#a8ff78', '#78ffd6']} style={styles.container} /&gt;
              } 
  </code></pre>
  
  <p>But it is not working.</p>