SpanStore: Guava support library

<!-- https://jarcasting.com/artifacts/io.zipkin.java/spanstore-guava/ -->
<dependency>
    <groupId>io.zipkin.java</groupId>
    <artifactId>spanstore-guava</artifactId>
    <version>0.10.4</version>
</dependency>

// https://jarcasting.com/artifacts/io.zipkin.java/spanstore-guava/
implementation 'io.zipkin.java:spanstore-guava:0.10.4'

// https://jarcasting.com/artifacts/io.zipkin.java/spanstore-guava/
implementation ("io.zipkin.java:spanstore-guava:0.10.4")

'io.zipkin.java:spanstore-guava:jar:0.10.4'

<dependency org="io.zipkin.java" name="spanstore-guava" rev="0.10.4">
  <artifact name="spanstore-guava" type="jar" />
</dependency>

@Grapes(
@Grab(group='io.zipkin.java', module='spanstore-guava', version='0.10.4')
)

libraryDependencies += "io.zipkin.java" % "spanstore-guava" % "0.10.4"

[io.zipkin.java/spanstore-guava "0.10.4"]