The graph is not showing gaps when temperature records are missing

[marthakeezy]

Describe the bug
A clear and concise description of what the bug is. Screenshots are great!

When temperature records are missing, the Cold Chain App is not showing gaps on a graph. The gaps are then visible in the omSupply app.

For example, one of the sensors was not logging temperature from 3:56am to 5:11am as seen below, but the graph appeared consistent.

Looking at the same timeframe in omSupply, the graph is showing a gap for the time period

To Reproduce
Steps to reproduce the behavior:

1. It is unclear why sometimes the sensors are not picking up temperature readings, but the first step to reproducing would be to have some missing temperature logs/data/readings. Possibly it is a good idea to connect 2/3 sensors to your Cold Chain app to speed up the process.
2. Once you have missing temperature readings, check the Cold Chain application and note the consistent graph.
3. Check the same timeframe in omSupply and note the gaps appearing.

Expected behavior
A clear and concise description of what you expected to happen.

It would be great to show the data consistently, e.g. if there are no temperature readings, then the graph should display a clear gap. Also if there is a gap in omSupply, there should be an identical graph shown in CCA because they show the same data for the same sensors, just in 2 different places.

Smartphone (please complete the following information):

• Device: [e.g. iPhone6] - A8 Samsung Tablet
• OS: [e.g. iOS8.1] Android
• Browser [e.g. stock browser, safari] N/A
• Version [e.g. 22] CCA 0.5.6

Additional context
Add any other context about the problem here.