[ASTERIXDB-2512][TEST] Adds SpiderSilk Integration

- user model changes: no
- storage format changes: no
- interface changes: no

details:
- Adds minimal SpiderSilk integration by adding the asterix-spidersilk module, reuqired maven
dependencies, sample Dockerfile for node's containers, simple config file for 3 node AsterixDB
cluster, a TestUtility to make working with SpiderSilk easier and a sample test case that uses
all of these together.

Change-Id: Ifd64aad26bd5cd3b6040fa53e87ae0d0d0c0a562
Reviewed-on: https://asterix-gerrit.ics.uci.edu/3053
Reviewed-by: Ian Maxon <imaxon@apache.org>
Tested-by: Ian Maxon <imaxon@apache.org>
diff --git a/.gitignore b/.gitignore
index 569eb3d..1dcc3c2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,3 +28,4 @@
 .m2*
 ß
 
+.SpiderSilkWorkingDirectory