Add support for aliases to package scanner.

package_scanner.nim

@@ -73,6 +73,12 @@ proc canFetchNimbleRepository(name: string, urlJson: JsonNode): bool =
       echo "W: Another error attempting to request: ", url
       echo "  Error was: ", getCurrentExceptionMsg()
 
+proc verifyAlias(pdata: JsonNode, result: var int) =
+  if not pdata.hasKey("name"):
+    echo "E: missing alias' package name"
+    result.inc()
+
+  # TODO: Verify that 'alias' points to a known package.
 
 proc check(): int =
   var
@@ -88,6 +94,9 @@ proc check(): int =
   for pdata in pkg_list:
     name = if pdata.hasKey("name"): pdata["name"].str else: nil
 
+    if pdata.hasKey("alias"):
+      verifyAlias(pdata, result)
+    else:
       if name.isNil:
         echo "E: missing package name"
         result.inc()