In pom.xml, have Maven surefire plugin skip tests by default

pom.xml

@@ -6,6 +6,7 @@
 	<version>1.3.7</version>
 	<packaging>jar</packaging>
 	<properties>
+		<skipTests>true</skipTests>
 		<bitcoinj.version>0.15.5</bitcoinj.version>
 		<bouncycastle.version>1.64</bouncycastle.version>
 		<build.timestamp>${maven.build.timestamp}</build.timestamp>
@@ -316,6 +317,9 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-surefire-plugin</artifactId>
 				<version>2.22.2</version>
+				<configuration>
+					<skipTests>${skipTests}</skipTests>
+				</configuration>
 			</plugin>
 		</plugins>
 		<pluginManagement>