Fix: destroy the zmq contexts when not needed anymore

Otherwise, they will be destroyed when Python decides to delete the objects, which
might cause problems during the tests

beat/core/agent.py

@@ -74,6 +74,10 @@ class Server(MessageHandler):
     ))
 
 
+  def destroy(self):
+    self.context.destroy()
+
+
   def __str__(self):
     return 'Server(%s)' % self.address
 
@@ -367,6 +371,7 @@ class Agent(object):
       self.db_process.rm()
       self.db_process = None
 
+    self.server.destroy()
     self.server = None
     return retval
 

beat/core/execution.py

@@ -152,6 +152,7 @@ class Executor(object):
     self.output_list = None
     self.data_sinks = []
     self.data_sources = []
+    self.context = None
 
     # runs validation if required
     self.errors = []
@@ -183,6 +184,7 @@ class Executor(object):
     self.output_list = None
     self.data_sinks = []
     self.data_sources = []
+    self.context = None
     self.db_address = None
 
     if not isinstance(data, dict): #user has passed a file pointer
@@ -268,6 +270,10 @@ class Executor(object):
     self.data_sources = []
     self.agent = None
 
+    if self.context is not None:
+        self.context.destroy()
+        self.context = None
+
 
   def _prepare_inputs(self):
     """Prepares all input required by the execution."""