Do not mention Maven.

Author: armiol

README.md

@@ -22,20 +22,6 @@ dependencies {
 }
 ```
 
-Maven:
-```xml
-  <!-- Datastore Storage support library. -->
-  <groupId>io.spine.gcloud</groupId>
-  <artifactId>spine-datastore</artifactId>
-  <version>1.0.0</version>
-  
-   <!-- Stackdriver Trace support library. -->
-   <groupId>io.spine.gcloud</groupId>
-   <artifactId>spine-stackdriver-trace</artifactId>
-   <version>1.0.0</version>
-
-```
-
 These artifacts should be used as a part of the Spine server application.
 
 For the details on setting up the server environment please refer to [Spine Bootstrap Gradle plugin](https://github.com/SpineEventEngine/bootstrap/)