support IPIP interface type for RedHat linux.
Add no_use_wheel option to pip.install
Fix linting error
Add no_use_wheel option to pip.installed
Fix error message command argument
Fix linting error
Add file_tree external pillar (should fix #13510).
Merge pull request #15088 from thatch45/develop

Merge #15009 with fixes
Merge pull request #15033 from ahammond/support_rhel_ipip

support IPIP interface type for RedHat linux.
Merge pull request #15036 from danielfrg/patch-2

Add no_use_wheel option to pip.install
Merge branch 'file_tree-for-develop' of https://github.com/imtx/salt into imtx-file_tree-for-develop
copy-edit the doc and use single quotes
Merge branch 'imtx-file_tree-for-develop' into develop