add missing plugin .gitignore

Signed-off-by: Hans-Erik Floryd <hans-erik.floryd@rt-labs.com>
diff --git a/org.eclipse.capra.ui.plantuml/.gitignore b/org.eclipse.capra.ui.plantuml/.gitignore
new file mode 100644
index 0000000..934e0e0
--- /dev/null
+++ b/org.eclipse.capra.ui.plantuml/.gitignore
@@ -0,0 +1,2 @@
+/bin
+/target