Release v0.1.6

Use 'pipe' variable format instead of default

Previously, when user selected multiple variables, this query

```
service ~= "$service"
```

was expanded into

```
service ~= "{svc1, svc2}"
```

After the change, it will be turned correctly into

```
service ~= "svc1|svc2"
```

We use `pipe` instead of `regex` because there seems to be a bug in
riemann that will make the following fail

```
host ~= "host1\.example\.com|host2\.example\.com"
```

pipe doesn't backslash the dot but this is a workaround

i

Release v0.1.5

Add support for Mirabelle

In Mirabelle https://github.com/mcorbin/Mirabelle websocket events
have timestamp in fractional seconds.

Release v0.1.4

Prepare for v0.1.4

Release v0.1.3

Fix dependency syntax

Second release

Hopefully last release before signing

Initial release

Releasing this plugin to an unsuspecting world