Add support for OkHttp3.

Fixes gh-63.

spring-cloud-vault-config-consul/pom.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 
 	<parent>
@@ -26,14 +27,8 @@
 		</dependency>
 
 		<dependency>
-			<groupId>org.apache.httpcomponents</groupId>
-			<artifactId>httpclient</artifactId>
-			<scope>test</scope>
-		</dependency>
-
-		<dependency>
-			<groupId>org.apache.httpcomponents</groupId>
-			<artifactId>httpcore</artifactId>
+			<groupId>com.squareup.okhttp3</groupId>
+			<artifactId>okhttp</artifactId>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>

spring-cloud-vault-config/pom.xml

@@ -64,6 +64,12 @@
 			<optional>true</optional>
 		</dependency>
 
+		<dependency>
+			<groupId>com.squareup.okhttp3</groupId>
+			<artifactId>okhttp</artifactId>
+			<optional>true</optional>
+		</dependency>
+
 	</dependencies>
 
 	<build>

spring-cloud-vault-dependencies/pom.xml

@@ -25,6 +25,7 @@
 		<httpcore.version>4.4.5</httpcore.version>
 		<netty.version>4.1.6.Final</netty.version>
 		<okhttp.version>2.7.5</okhttp.version>
+		<okhttp3.version>3.4.2</okhttp3.version>
 		<slf4j.version>1.7.21</slf4j.version>
 	</properties>
 
@@ -118,6 +119,13 @@
 				<optional>true</optional>
 			</dependency>
 
+			<dependency>
+				<groupId>com.squareup.okhttp3</groupId>
+				<artifactId>okhttp</artifactId>
+				<version>${okhttp3.version}</version>
+				<optional>true</optional>
+			</dependency>
+
 			<!-- Logging -->
 			<dependency>
 				<groupId>org.slf4j</groupId>