Refactored authorization header builders

Simplified the creation of new properties for the headers and new builders
Added new builders and the correspondant tests

Author: alpegon

README.md

@@ -13,7 +13,7 @@ The javadoc for this project can be found here: [Javadoc](http://indigo-dc.githu
 1.1 REQUISITES
 --------------
 This project has been created with maven.
-To compile it you will need at least **Apache Maven 3.0.5** and **Java 1.7**.
+To compile it you will need at least **Apache Maven 3.0.5** and **Java 1.8**.
 Maven will take care of downloading all the extra dependencies needed for the project.
 
 1.2 INSTALLING
@@ -57,3 +57,17 @@ InfrastructureUri newInfrastructureUri = im.createInfrastructure(readFile(TOSCA_
 im.destroyInfrastructure(getInfrastructureId());
 ```
 The 'im' client always returns a POJO with the information of the call. If an error occurs, an **ImClientErrorException** is thrown. This exception contains the error message and the error code returned by the server.
+
+### 1.4.3 Create authorization headers
+Since version 0.4.5 the infrastructure manager allows to use the **AuthorizationHeader** class and different builders to create the authorization headers.
+The usage is as follows:
+```
+AuthorizationHeader ah = new AuthorizationHeader();
+Credentials imCred = ImCredentials.buildCredentials().withUsername("user").withPassword("pass");
+Credentials vmrcCred = VmrcCredentials.buildCredentials().withUsername("user").withPassword("pass").withHost("host");
+Credentials dummyCred = DummyCredential.buildCredentials();
+ah.addCredential(imCred);
+ah.addCredential(vmrcCred);
+ah.addCredential(dummyCred);
+InfrastructureManager im = new InfrastructureManager("IM_ENDPOINT", ah);
+```

pom.xml

@@ -3,7 +3,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>es.upv.i3m.grycap</groupId>
   <artifactId>im-java-api</artifactId>
-  <version>0.4.5</version>
+  <version>0.4.6</version>
   <name>IM Java API</name>
   <description>Java client for the REST API of the IM</description>
 
@@ -16,7 +16,7 @@
     <apache-commons.version>3.4</apache-commons.version>
     <junit.version>4.12</junit.version>
     <log4j.version>1.2.17</log4j.version>
-    <java.version>7</java.version>
+    <java.version>8</java.version>
     <maven-javadoc-plugin.version>2.10.3</maven-javadoc-plugin.version>
     <maven-checkstyle-plugin.version>2.17</maven-checkstyle-plugin.version>
     <mockserver-netty.version>3.10.4</mockserver-netty.version>