Testng dependency back to 7.5.1

Author: thboileau

pom.xml

@@ -100,7 +100,7 @@
         <lib-sun-istack-version>3.0.12</lib-sun-istack-version>
         <lib-stax2-version>3.1.4</lib-stax2-version>
         <lib-swagger-version>1.5.3-M1</lib-swagger-version>
-        <lib-testng-version>7.11.0</lib-testng-version>
+        <lib-testng-version>7.5.1</lib-testng-version>
         <lib-thymeleaf-version>3.1.3.RELEASE</lib-thymeleaf-version>
         <lib-velocity-version>2.4.1</lib-velocity-version>
         <lib-woodstock-core-version>4.4.1</lib-woodstock-core-version>