Create CODEOWNERS (#289)

* Create CODEOWNERS

* Update CODEOWNERS
diff --git a/CODEOWNERS b/CODEOWNERS
new file mode 100644
index 0000000..78901bf
--- /dev/null
+++ b/CODEOWNERS
@@ -0,0 +1 @@
+* @nlopezgi @xingao267 @smukherj1 @alex1545