Release v1.7.3 (#526)

diff --git a/CHANGELOG b/CHANGELOG
index 0426d39..eb4afea 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,11 @@
+v1.7.3
+  Version 1.7.3
+
+  Bugfix release
+
+  - Make apiclient.sample_tools gracefully fail to import (#525).
+
+
 v1.7.2
   Version 1.7.2
 
diff --git a/googleapiclient/__init__.py b/googleapiclient/__init__.py
index 81ebaf3..5b4ca88 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__ = "1.7.2"
+__version__ = "1.7.3"
 
 # Set default logging handler to avoid "No handler found" warnings.
 import logging