Add vim swp files to gitignore.

Signed-off-by: Warren Turkal <wt@penguintechs.org>

--
Change-Id: I2d45a959f104171810073cc5ed6bddb1ecbb2a0b
Reviewed-on: https://bazel-review.googlesource.com/#/c/2391/
MOS_MIGRATED_REVID=108988222
diff --git a/.gitignore b/.gitignore
index 388c82c..06f4d0f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+.*.swp
 *~
 /output/
 /bazel-bin