Not being able to enable PWM using the HAL TIM library on stm32f0
Thanks to a kind suggestion I was able to get the PWM working using the TIM_PWMOutput example under the STM32F0 CubeMX firmware: 

STM32Cube_FW_F0_V1.5.0\Projects\STM32F0308Discovery\Examples\TIM\TIM_PWMOutput

I have now solved my problem using the code from the example. Though I am not sure where it is different from the code generated by CubeMX.