Prepare for 0.1.8 release (#339)

Author: liyanhui1228

opencensus/trace/exporters/stackdriver_exporter.py

@@ -25,7 +25,7 @@
     import MonitoredResourceUtil
 
 # OpenCensus Version
-VERSION = '0.1.7'
+VERSION = '0.1.8'
 
 # Agent
 AGENT = 'opencensus-python [{}]'.format(VERSION)

setup.py

@@ -28,7 +28,7 @@
 
 setup(
     name='opencensus',
-    version='0.1.7',
+    version='0.1.8',
     author='OpenCensus Authors',
     author_email='[email protected]',
     classifiers=[