Remove Docker test dependency (#1753)

It was only used by Electrum which was removed in #1750

BUILD.md

@@ -4,7 +4,6 @@
 
 - [OpenJDK 11](https://adoptopenjdk.net/?variant=openjdk11&jvmVariant=hotspot).
 - [Maven](https://maven.apache.org/download.cgi) 3.6.0 or newer
-- [Docker](https://www.docker.com/) 18.03 or newer (optional) if you want to run all tests
 
 ## Build
 
@@ -22,7 +21,6 @@ Notes:
 
 - This command will build all modules (core, node, gui).
 - If the build fails, you may need to clean previously built artifacts with the `mvn clean` command.
-- Some tests use [Docker](https://www.docker.com/), so make sure your docker daemon is running.
 - Archives can be found in the `target` folder for each module.
 
 ### Skip tests

eclair-core/pom.xml

@@ -265,25 +265,6 @@
             <version>1.5.0</version>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>com.whisk</groupId>
-            <artifactId>docker-testkit-scalatest_${scala.version.short}</artifactId>
-            <version>0.9.9</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>com.whisk</groupId>
-            <artifactId>docker-testkit-impl-spotify_${scala.version.short}</artifactId>
-            <version>0.9.9</version>
-            <scope>test</scope>
-        </dependency>
-	<!-- neeeded for our docker tests, see  https://github.com/spotify/dockerfile-maven/issues/90 -->
-        <dependency>
-            <groupId>javax.activation</groupId>
-            <artifactId>activation</artifactId>
-            <version>1.1.1</version>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>com.typesafe.akka</groupId>
             <artifactId>akka-testkit_${scala.version.short}</artifactId>