Fix install instructions in release notes

Author: aaltat

tasks.py

@@ -28,13 +28,13 @@
 
 ::
 
-   pip install --pre --upgrade robotframework-robotlibcore
+   pip install --pre --upgrade pip install robotframework-pythonlibcore
 
 to install the latest available release or use
 
 ::
 
-   pip install robotframework-robotlibcore=={version}
+   pip install pip install robotframework-pythonlibcore=={version}
 
 to install exactly this version. Alternatively you can download the source
 distribution from PyPI_ and install it manually.