SEBA-563 fix networkx to version 2.2

Change-Id: Ie4b336ac8694fb9752c7110ee4e27edc67b3bb6f
diff --git a/lib/xos-synchronizer/requirements.txt b/lib/xos-synchronizer/requirements.txt
index 3fde4f8..bc519e7 100644
--- a/lib/xos-synchronizer/requirements.txt
+++ b/lib/xos-synchronizer/requirements.txt
@@ -3,7 +3,7 @@
 confluent-kafka==0.11.5
 inflect~=2.1.0
 multistructlog~=2.1.0
-networkx~=2.2
+networkx==2.2
 six~=1.12.0
 xosconfig~=3.0.1
 xosgenx~=3.0.1