Add plugin versions for deploy, dependency and gpg plugins.

Fixes gh-32.

pom.xml

@@ -243,6 +243,18 @@
 					<version>2.5.3</version>
 				</plugin>
 
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-deploy-plugin</artifactId>
+					<version>2.8.2</version>
+				</plugin>
+
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-dependency-plugin</artifactId>
+					<version>2.10</version>
+				</plugin>
+
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-site-plugin</artifactId>
@@ -256,6 +268,12 @@
 					</dependencies>
 				</plugin>
 
+				<plugin>
+					<groupId>org.apache.maven.plugins</groupId>
+					<artifactId>maven-gpg-plugin</artifactId>
+					<version>1.6</version>
+				</plugin>
+
 				<plugin>
 					<groupId>org.codehaus.mojo</groupId>
 					<artifactId>animal-sniffer-maven-plugin</artifactId>
@@ -293,7 +311,9 @@
 
 	<profiles>
 		<profile>
+
 			<id>springNext</id>
+
 			<properties>
 				<spring.version>4.3.5.BUILD-SNAPSHOT</spring.version>
 			</properties>
@@ -309,7 +329,9 @@
 			</repositories>
 		</profile>
 		<profile>
+
 			<id>spring5</id>
+
 			<properties>
 				<spring.version>5.0.0.BUILD-SNAPSHOT</spring.version>
 			</properties>
@@ -360,6 +382,7 @@
 				<plugins>
 
 					<plugin>
+						<groupId>org.apache.maven.plugins</groupId>
 						<artifactId>maven-gpg-plugin</artifactId>
 						<executions>
 							<execution>
@@ -389,7 +412,6 @@
 					<plugin>
 						<groupId>org.apache.maven.plugins</groupId>
 						<artifactId>maven-javadoc-plugin</artifactId>
-						<version>2.10.3</version>
 						<executions>
 							<execution>
 								<goals>