Merge pull request #476 from powerapi-ng/chore/release-v2.9.0

chore(release): Prepare for PowerAPI release v2.9.0

Author: gfieni

src/powerapi/__init__.py

@@ -27,4 +27,4 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-__version__ = "2.8.0"
+__version__ = "2.9.0"