fix travis build

Signed-off-by: Lukas Jungmann <lukas.jungmann@oracle.com>

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index 7f0767d..a7ffce5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,6 +11,9 @@
 
 dist: bionic
 
+git:
+  depth: false
+
 jdk:
   - oraclejdk11
   - oraclejdk14