Policy Coverage (#149)

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

src/engine.rs

@@ -458,4 +458,14 @@ impl Engine {
     pub fn get_coverage_report(&self) -> Result<crate::coverage::Report> {
         self.interpreter.get_coverage_report()
     }
+
+    #[cfg(feature = "coverage")]
+    pub fn set_enable_coverage(&mut self, enable: bool) {
+        self.interpreter.set_enable_coverage(enable)
+    }
+
+    #[cfg(feature = "coverage")]
+    pub fn clear_coverage_data(&mut self) {
+        self.interpreter.clear_coverage_data()
+    }
 }