Add back COPYING file

akoeplinger · akoeplinger · commit 3ddd156b1442 · 2017-09-20T20:31:33.000+02:00
It was removed in e1fb6fe but it's actually needed by a few autotools tools.
diff --git a/COPYING b/COPYING
@@ -0,0 +1 @@
+See LICENSE file in the project root for full license information.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+See LICENSE file in the project root for full license information.`