travis: Fixing hard coded 'master' in install script.
travis: Fixing hard coded 'master' in install script.

timvideos/conda-misoc-lm32,timvideos/conda-hdmi2usb-packages,SymbiFlow/conda-packages,litex-hub/litex-conda-compilers,SymbiFlow/conda-packages,timvideos/conda-hdmi2usb-packages,litex-hub/litex-conda-prog,timvideos/conda-misoc-lm32,litex-hub/litex-conda-eda