Update version and changelog for v1.5.2
diff --git a/CHANGELOG b/CHANGELOG
index 16ef00f..c31790c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,14 @@
+v1.5.2
+  Version 1.5.2
+
+  Bugfix release
+
+  - Allow using oauth2client >= 1.5.0, < 4.0.0. (#265)
+  - Fix project_id argument description. (#257)
+  - Retry chunk uploaded on rate limit exceeded errors. (#255)
+  - Obtain access token if necessary in BatchHttpRequest.execute(). (#232)
+  - Warn when running tests using HttpMock without having a cache. (#261)
+
 v1.5.1
   Version 1.5.1
 
diff --git a/googleapiclient/__init__.py b/googleapiclient/__init__.py
index 26442ac..b911ff0 100644
--- a/googleapiclient/__init__.py
+++ b/googleapiclient/__init__.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "1.5.1"
+__version__ = "1.5.2"
 
 # Set default logging handler to avoid "No handler found" warnings.
 import logging