Prepare for 0.6.1 release. (#210)

Author: tswast

docs/source/changelog.rst

@@ -3,7 +3,7 @@ Changelog
 
 .. _changelog-0.6.1:
 
-0.6.1 / [unreleased]
+0.6.1 / 2018-09-11
 --------------------
 
 - Improved ``read_gbq`` performance and memory consumption by delegating

release-procedure.md

@@ -1,3 +1,14 @@
+*   Add current date to `docs/source/changelog.rst`.
+
+*   Send PR to prepare release on scheduled date.
+
+*   Verify you are on the latest changes. `rebase -i` should be noop.
+
+        git fetch pandas-gbq master
+        git checkout master
+        git rebase -i pandas-gbq/master
+        git diff pandas-gbq/master
+
 *   Tag commit
 
         git tag -a x.x.x -m 'Version x.x.x'