Java env alpha (#656)

This change adds support for JVM based environment for running Java functions. This is alpha release of JVM environment and might undergo changes.

examples/jvm/java/src/main/java/io/fission/HelloWorld.java

@@ -0,0 +1,16 @@
+package io.fission;
+
+import org.springframework.http.RequestEntity;
+import org.springframework.http.ResponseEntity;
+
+import io.fission.Function;
+import io.fission.Context;
+
+public class HelloWorld implements Function {
+
+	@Override
+	public ResponseEntity<?> call(RequestEntity req, Context context) {
+		return ResponseEntity.ok("Hello World!");
+	}
+
+}

examples/jvm/java/src/test/java/io/fission/HelloWorldTest.java

@@ -0,0 +1,24 @@
+package io.fission;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.RequestEntity;
+import org.springframework.http.ResponseEntity;
+import org.springframework.util.Assert;
+
+public class HelloWorldTest {
+
+	public void testResponse() {
+		HelloWorld hw = new HelloWorld();
+		RequestEntity request = null;
+		try {
+			request = RequestEntity.get(new URI("http://example.com/bar")).build();
+		} catch (URISyntaxException e) {
+			e.printStackTrace();
+		}
+		ResponseEntity resp = hw.call(request, null);
+		Assert.hasText(resp.getBody().toString(), "Hello World!");
+	}
+}