Adding downloadonly support to yum/dnf module

salt/modules/yumpkg.py

@@ -913,6 +913,7 @@ def install(name=None,
             skip_verify=False,
             pkgs=None,
             sources=None,
+            downloadonly=False,
             reinstall=False,
             normalize=True,
             **kwargs):
@@ -970,6 +971,9 @@ def install(name=None,
     skip_verify
         Skip the GPG verification check (e.g., ``--nogpgcheck``)
 
+    downloadonly
+        Only download the packages, do not install.
+
     version
         Install a specific version of the package, e.g. 1.2.3-4.el5. Ignored
         if "pkgs" or "sources" is passed.
@@ -1200,6 +1204,8 @@ def install(name=None,
                 cmd.extend(args)
         if skip_verify:
             cmd.append('--nogpgcheck')
+        if downloadonly:
+            cmd.append('--downloadonly')
 
     errors = []