[bug] red null's in manual trade mode

[infatrus]

System information

• OS Platform and Distribution: Ubuntu 16.04.3 LTS (Xenial Xerus)
• Zenbot version: unstable
• NodeJS version: 8.9.4
• Python version: -
• Exact command to reproduce: ./zenbot.sh trade --manual poloniex.DGB-BTC --strategy=bollinger --period_length=15m --period=15m

Describe the problem

When in manual trade mode, sell signals are not clearly visible between null's (both are red), should be grey (or other neutral color).

Source code / logs

2018-01-12 13:15:00 0.00000733 DGB-BTC +0.41% 1.33m 66 +++ +00.0000 00 00 null
2018-01-12 13:30:00 0.00000735 DGB-BTC +0.27% 3.79m 67 +++ +00.0000 00 00 null
2018-01-12 13:45:00 0.00000741 DGB-BTC +0.81% 1.06m 71 +++ +00.0000 00 00 sell
2018-01-12 14:00:00 0.00000738 DGB-BTC -0.41% 1.85m 67 +++ +00.0000 00 00 null
2018-01-12 14:15:00 0.00000729 DGB-BTC -1.22% 862.96k 57 ++ +00.0000 00 00 null

[Shawn8901]

seems for me as a bug, that the bollinger strat sets the string 'null' instead a "real" null. So the code which chooses the color isn't working.
On other strategies there is nothing shown if there is no signal given by the strategy.

[infatrus]

That's it:
Line 34 of ./extensions/strategy/bollinger/strategy.js

There is:

• s.signal = 'null' // hold

Should be:

• s.signal = null // hold