Getting problem in Running Rasa Stack starter-pack

I am getting below error when I am running command “pip install -r requirements.txt”.

Could not find a version that satisfies the requirement tensorflow==1.10.0 (from -r requirements.txt (line 12)) (from versions: )

I am having Python 3.6 . Due to this error … I am not able to proceed to run the Rasa stack starter pack

Which OS are you using?

I am using windows 7.