MULE-6800: Thread leak on Mule redeployments for embedded

_Disabling those threads do not have to run on embedded mules.
_Removing old test classes that are duplicated (there are a duplciate class with suffix TestCase instead of Test)
_Adding dependency to mule-core for tests ONLY in order to reuse the testing framework
MULE-6800: Thread leak on Mule redeployments for embedded

_ Updating test to use expected exception attribute
Merge pull request #91 from mulesoft/MULE-6800

MULE-6800: Thread leak on Mule redeployments for embedded