Test that auto configurations can be added by init scripts

When an init command is run, it may add entries to the classpath. This
commit adds a test that verifies that, if an entry that is added to
the classpath contains a CompilerAutoConfiguration file in
META-INF/services, then the CompilerAutoConfigurations declared in it
are found by subsequent ServiceLoader.load calls.

spring-boot-cli/src/test/java/cli/command/CustomCompilerAutoConfiguration.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012-2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cli.command;
+
+import groovy.lang.GroovyClassLoader;
+
+import org.codehaus.groovy.ast.ClassNode;
+import org.codehaus.groovy.classgen.GeneratorContext;
+import org.codehaus.groovy.control.CompilationFailedException;
+import org.codehaus.groovy.control.SourceUnit;
+import org.springframework.boot.cli.compiler.CompilerAutoConfiguration;
+import org.springframework.boot.cli.compiler.GroovyCompilerConfiguration;
+
+/**
+ * @author Andy Wilkinson
+ */
+public class CustomCompilerAutoConfiguration extends CompilerAutoConfiguration {
+
+	@Override
+	public void apply(GroovyClassLoader loader,
+			GroovyCompilerConfiguration configuration, GeneratorContext generatorContext,
+			SourceUnit source, ClassNode classNode) throws CompilationFailedException {
+		System.out.println("Customising compiler configuration");
+	}
+
+}