bump up version to 2.6.0

Author: krasoffski

setup.py

@@ -3,12 +3,12 @@
 setup(
     name='reportportal-client',
     packages=find_packages(),
-    version='2.5.5',
+    version='2.6.0',
     description='Python client for Report Portal',
     author='Artsiom Tkachou',
     author_email='[email protected]',
     url='https://github.com/reportportal/client-Python',
-    download_url='https://github.com/reportportal/client-Python/tarball/2.5.5',
+    download_url='https://github.com/reportportal/client-Python/tarball/2.6.0',
     keywords=['testing', 'reporting', 'reportportal'],
     classifiers=[],
     install_requires=["requests>=2.4.2"],