prepare release 4.1.8

Author: Mark

Diff for: ChangeLog

@@ -1,4 +1,4 @@
-v4.1.8 (2017-02-xx)
+v4.1.8 (2017-02-03)
 ---------------------------
 * changed java.util.Date serialization from VPack.date to VPack.string (ISO 8601)
 * changed java.sql.Date serialization from VPack.date to VPack.string (ISO 8601)

Diff for: pom.xml

@@ -4,7 +4,7 @@
 
 	<groupId>com.arangodb</groupId>
 	<artifactId>arangodb-java-driver</artifactId>
-	<version>4.1.8-SNAPSHOT</version>
+	<version>4.1.8</version>
 	<inceptionYear>2016</inceptionYear>
 	<packaging>jar</packaging>
 
@@ -23,6 +23,7 @@
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<slf4j-api.version>1.7.13</slf4j-api.version>
+		<json-simple.version>1.1.1</json-simple.version>
 		<logback-classic.version>1.1.3</logback-classic.version>
 		<hamcrest-all.version>1.3</hamcrest-all.version>
 		<junit.version>4.12</junit.version>
@@ -230,7 +231,7 @@
 			<dependency>
 			    <groupId>com.googlecode.json-simple</groupId>
 			    <artifactId>json-simple</artifactId>
-			    <version>1.1.1</version>
+			    <version>${json-simple.version}</version>
 			</dependency>
 			<dependency>
 				<groupId>ch.qos.logback</groupId>