Update change log for minor release

ccoffrin · web-flow · commit 211200a59be6 · 2018-05-31T09:39:22.000-07:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,10 @@ PowerModels.jl Change Log
 =================
 
 ### Staged
+- nothing
+
+### v0.7.1
+- Added warning when data is missing in a PTI file
 - Minor tidying of matpower test cases
 - Relaxed variable bounds in BFM to be consistent with BIM
 
