[fix] style warnings for text and SVG

Allow 'fill' as a valid style property.
Allow 'textAlignVertical' to be any string.

src/apis/StyleSheet/StyleSheetValidation.js

@@ -91,6 +91,7 @@ StyleSheetValidation.addValidStylePropTypes({
   borderSpacing: oneOf([number, string]),
   clear: string,
   cursor: string,
+  fill: string,
   float: oneOf(['left', 'none', 'right']),
   font: string /* @private */,
   listStyle: string,

src/components/Text/TextStylePropTypes.js

@@ -30,7 +30,7 @@ const TextStylePropTypes = {
   letterSpacing: numberOrString,
   lineHeight: numberOrString,
   textAlign: TextAlignPropType,
-  textAlignVertical: oneOf(['auto', 'bottom', 'center', 'top']),
+  textAlignVertical: string,
   textDecorationColor: ColorPropType,
   textDecorationLine: string,
   textDecorationStyle: string,