Test failing during build

[mattia-hash]

Hi, tests seem to be failing during build. See errors below.

`> Task :test FAILED

com.pega.api2swagger.ModelPropertyTest > extractProperties FAILED
java.lang.NoClassDefFoundError at ModelPropertyTest.java:22
Caused by: java.lang.ClassNotFoundException at ModelPropertyTest.java:22

com.pega.api2swagger.SwaggerSerializerTest > writeSpecWithParameterReferences FAILED
java.lang.NoClassDefFoundError at SwaggerSerializerTest.java:129

com.pega.api2swagger.SwaggerSerializerTest > convertSpec FAILED
java.lang.NoClassDefFoundError at SwaggerSerializerTest.java:41

com.pega.api2swagger.updater.TestSwaggerUpdater > testAddNewPath FAILED
java.lang.NoClassDefFoundError at TestSwaggerUpdater.java:34
Caused by: java.lang.ClassNotFoundException at TestSwaggerUpdater.java:34

35 tests completed, 4 failed

FAILURE: Build failed with an exception.`

[joshi-adi-1983]

please try installing jdk8 and retry.