akashihi/mdg-rate-loader: main.go; 3 LoC

Found a possible issue in [akashihi/mdg-rate-loader](https://www.github.com/akashihi/mdg-rate-loader) at [main.go](https://github.com/akashihi/mdg-rate-loader/blob/2d647f84851557115450ff67016c9cacc404e300/main.go#L56-L58)

Below is the message reported by the analyzer for this snippet of code. Beware that the analyzer only reports the first
issue it finds, so please do not limit your consideration to the contents of the below message.

> function call at line 57 passes reference to rate to third-party code

[Click here to see the code in its original context.](https://github.com/akashihi/mdg-rate-loader/blob/2d647f84851557115450ff67016c9cacc404e300/main.go#L56-L58)

Click here to show the 3 line(s) of Go which triggered the analyzer.

```go
for _, rate := range ratePairs {
service.store(&rate)
}

```

Click here to show extra information the analyzer produced.

```
No path was found through the callgraph that could lead to a function which writes a pointer argument.

The following graphviz dot graph describes paths through the callgraph that could lead to a function which passes a pointer to third-party code:
digraph G {
"(SaveRate, 1)" -> {}
"(store, 1)" -> {"(setRate, 1)";}
"(setRate, 1)" -> {"(SaveRate, 1)";}
}

```

Leave a reaction on this issue to contribute to the project by classifying this instance as a **Bug** :-1:, **Mitigated** :+1:, or **Desirable Behavior** :rocket:
See the descriptions of the classifications [here](https://github.com/github-vet/rangeclosure-findings#how-can-i-help) for more information.

commit ID: 2d647f84851557115450ff67016c9cacc404e300

Read main.go lines 56-58 and the analyzer explanation, then inspect the store, setRate, and SaveRate path named in the issue. Decide whether passing &rate is a bug, mitigated, or desirable behavior, and record the classification using the requested reaction.

Written by the indexing model from the issue text.