[3] Pendulum Trading Template should allow a price feed for the seed price

[nikhilsaraf]

Desired Behavior

I want to be able to restart a bot configured from the Pendulum trading template without having to re-configure the SEED_PRICE field every time.

Impact

The desired behavior will allow me to reduce my risk while running Kelp

Feature Suggestion

We can achieve the desired behavior by adding a price feed as a price source for the SEED_PRICE instead of a fixed price. This will fetch the price once when the bot starts up.