demo_data.json built using multiple smaller log files - issue with start and end speeds

[gdincu]

demo_data.json built using multiple smaller log files might cause the following issues:

• Incorrectly boosting the DriveTime value WHEN the last node from log1 has a speedKmh value > 0 & the first node from log2 also has a speedKmh value > 0
• Incorrectly boosting the IdleTime value WHEN the first node from log2 also has a speedKmh value equal to 0

**Basically for it to work as expected the correct setup at the moment needs to be as follows:

• The last node from log1 needs to have a speedKmh value = 0
• The first node from log2 needs to have a speedKmh value > 0**