Hitting 10k timesteps seems to be not achievable
in the 900 second time limit. This means that the
reward threshold must be met in order for the
experiment to terminate. This algorithm is seed
sensitive on this environment, so I toyed with the reward
threshold on various seeds, and ended up fixing the
reward threshold for a certain seed. This should
give us regression information, while eliminating the
possiblilty that the test flakes.

…nge n_step from 3 to 1

…threshold on corresponding regression test

…f policy rl algos

…ake_sac_pendulum

…significantly slower runtime with tf2 eager than other frameworks