Check AUR package for existence and add “deleted” message

aur.py

@@ -34,6 +34,7 @@ class AURPackage:
         self.package_base = None
         self.out_of_date = None
         self.last_modified = None
+        self._exists = False
         self._load(name)
 
 
@@ -48,6 +49,7 @@ class AURPackage:
         if response.status == 200:
             data = json.loads(response.data.decode('utf-8'))
             if data['resultcount'] > 0:
+                self._exists = True
                 values = data['results']
                 self.version = values['Version']
                 self.desc = values['Description']
@@ -63,6 +65,10 @@ class AURPackage:
             print("error:", response.status)
 
 
+    def exists(self):
+        return self._exists
+
+
     def get_name(self):
         """Get name."""
         return self.name