readme fix

README.md

-#### integration testing
-
-Integration tests that validate the argo stack, leveraging the
-'argopkgs' repository. The intended usage is to override (some of) the
-source(s) with WIP version(s), as part of development or continuous
-integration.
-
-### Usage
-
--   \[**1**\] Get Nix: `curl https://nixos.org/nix/install | sh`
-
--   \[**2**\] Use the `test` attribute of the argotest' nix attribute
-    set to enter a test environment. For example, we can run default
-    tests on the "argopkgs-pinned" version of argo components using:
-
-``` {.bash}
-nix-shell -E '
-let
-  argotest-src =
-    builtins.fetchGit {
-      url = https://xgitlab.cels.anl.gov/argo/argotest.git;
-      ref="master";
-    };
-  argotest = import argotest-src {};
-in
-  argotest.test'
-```
-
-### Hacking
-
--   edit `.README.md` in place of README.md and generate using
-    `./shake.hs`
+#### deprecated