fix: set google-cloud-conformance-tests to test scope (#44)

Author: BenWhitehead

google-cloud-firestore/pom.xml

@@ -171,6 +171,7 @@
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-conformance-tests</artifactId>
       <version>0.0.2</version>
+      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>com.fasterxml.jackson.core</groupId>