Fixing matplotlib to 3.0.3

Change-Id: I68a8ae6b7a561608b782c13cb9c21f8d9ce2b7fb
diff --git a/requirements.txt b/requirements.txt
index 0d8dad2..7952b24 100755
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,7 +11,7 @@
 git+https://github.com/zdw/robotframework-importresource@b81b87aabaee0594e966687b41e3674b866f28ee
 cord-robot==2.1.8
 virtualenv
-matplotlib>=3.0.3
+matplotlib==3.0.3
 requests==2.24.0
 grpc-robot>=2.9.3
 kafka-robot>=2.3.2