Release 0.15b0 (Part 2/2) bump version to 0.16.dev0

- Update version.py files
- Unpin `opentelemetry-{api,sdk}` versions in each package's `setup.cfg` file

Author: aabmass

opentelemetry-exporter-google-cloud/setup.cfg

@@ -27,8 +27,8 @@ packages=find_namespace:
 install_requires =
     google-cloud-monitoring <2.0.0
     google-cloud-trace >=0.24.0, <1.0.0
-    opentelemetry-api==0.15b0
-    opentelemetry-sdk==0.15b0
+    opentelemetry-api
+    opentelemetry-sdk
 
 [options.packages.find]
 where = src

opentelemetry-exporter-google-cloud/src/opentelemetry/exporter/google/version.py

@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "0.15b0"
+__version__ = "0.16.dev0"

opentelemetry-tools-google-cloud/setup.cfg

@@ -26,8 +26,8 @@ package_dir=
 packages=find_namespace:
 install_requires =
     google-auth~=1.22
-    opentelemetry-api==0.15b0
-    opentelemetry-sdk==0.15b0
+    opentelemetry-api
+    opentelemetry-sdk
     requests~=2.24
 
 [options.packages.find]

opentelemetry-tools-google-cloud/src/opentelemetry/tools/google/version.py

@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "0.15b0"
+__version__ = "0.16.dev0"