Use head pip artifacts in build+test environment (#308)
Use head pip artifacts in build+test environment (#308)

The previous links, based on specific versions (1.3.0rc1), are not
stable and will change with each and every release. The links here,
with fixed name "head" is stable and will never change (until TF 2 comes
out).
agrubb/tensorboard,ioeric/tensorboard,agrubb/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,ioeric/tensorboard,francoisluus/tensorboard-supervise,francoisluus/tensorboard-supervise,ioeric/tensorboard,qiuminxu/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,francoisluus/tensorboard-supervise,agrubb/tensorboard,qiuminxu/tensorboard,tensorflow/tensorboard,qiuminxu/tensorboard,agrubb/tensorboard,qiuminxu/tensorboard,ioeric/tensorboard,ioeric/tensorboard,francoisluus/tensorboard-supervise,francoisluus/tensorboard-supervise,ioeric/tensorboard,francoisluus/tensorboard-supervise,tensorflow/tensorboard,agrubb/tensorboard,tensorflow/tensorboard,agrubb/tensorboard