Add .gitignore for VS Code Generated maven project files

When VS Code detects a Maven project, it automatically generates
a bunch of Eclipse files to describe the project.

These are now ignored in order to not pollute the repository

Author: JLLeitschuh

java/ql/test/query-tests/maven-dependencies/.gitignore

@@ -0,0 +1,6 @@
+# These files are automatically generated by VS Code and should not be checked in
+*/.classpath
+*/.project
+*/target/*
+*/.settings/
+.project