travis: Install conda-verify.
travis: Install conda-verify.

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