Default snippet encoding to UTF-8 and make it configurable

Previously, snippets were written to disk using the JVM’s default
encoding. While this could be controlled by the file.encoding system
property it was not ideal as, if the proper was not always set, it could
lead to platform-dependent output being generated. Furthermore,
Asciidoctor uses UTF-8 encoding by default so there was a risk of the
snippets being generated in a different encoding to the encoding
expected by Asciidoctor.

This commit updates the configuration so that, by default, snippets are
encoded as UTF-8. The RestDocumentationConfigurer API has been enhanced
to allow this default to be configured as part of building the
MockMvc instance. This enhancement as brought with it a more fluent
configuration API that separates configuration that is related to URIs
from configuration that is related to snippets.

Closes gh-67

samples/rest-notes-spring-data-rest/src/test/java/com/example/notes/ApiDocumentation.java

@@ -18,6 +18,7 @@ package com.example.notes;
 
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.notNullValue;
+import static org.springframework.restdocs.RestDocumentation.documentationConfiguration;
 import static org.springframework.restdocs.RestDocumentation.document;
 import static org.springframework.restdocs.hypermedia.HypermediaDocumentation.linkWithRel;
 import static org.springframework.restdocs.payload.PayloadDocumentation.fieldWithPath;
@@ -40,7 +41,6 @@ import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.SpringApplicationConfiguration;
 import org.springframework.hateoas.MediaTypes;
-import org.springframework.restdocs.config.RestDocumentationConfigurer;
 import org.springframework.restdocs.payload.FieldType;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.test.context.web.WebAppConfiguration;
@@ -72,7 +72,18 @@ public class ApiDocumentation {
 	@Before
 	public void setUp() {
 		this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context)
-				.apply(new RestDocumentationConfigurer()).build();
+				.apply(documentationConfiguration()).build();
+		this.mockMvc = MockMvcBuilders
+				.webAppContextSetup(this.context)
+				.apply(documentationConfiguration()
+					.uris()
+						.withScheme("https")
+						.withHost("localhost")
+						.withPort(8443)
+					.and().snippets()
+						.withEncoding("ISO-8859-1"))
+				.build();
+
 	}
 
 	@Test