Provide support for documenting path parameters

This commit adds support for documenting a request's path parameters.
For example:

mockMvc.perform(
		get("/locations/{latitude}/{longitude}", 51.5072, 0.1275))
			.andExpect(status().isOk())
			.andDo(document("locations").withPathParameters(
					parameterWithName("latitude")
							.description("The location's latitude"),
					parameterWithName("longitude")
							.description("The location's longitude")
			));

Closes gh-86

docs/build.gradle

@@ -18,4 +18,5 @@ asciidoctor {
 	}
 	attributes	'revnumber': project.version,
 				'branch-or-tag': project.version.endsWith('SNAPSHOT') ? 'master': "v${project.version}"
+	inputs.files(sourceSets.test.java)
 }