[google_maps_flutter] Widget based polyline support for google maps. (f…

…irebase#1049)

- Adds supports for polylines.

AUTHORS

@@ -27,6 +27,8 @@ Sarthak Verma <[email protected]>
 Mike Diarmid <[email protected]>
 Invertase <[email protected]>
 Elliot Hesp <[email protected]>
+Aawaz Gyawali <[email protected]>
+EUI Limited <[email protected]>
 Katarina Sheremet <[email protected]>
 Thomas Stockx <[email protected]>
 Sarbagya Dhaubanjar <[email protected]>