Fix catchall except statments

Enable style check for catchall except statments
Fix up existing problems with catch-all's

fix period

Testing Done:
CI succeeds https://travis-ci.org/pantsbuild/pants/builds/85614655
CI running https://travis-ci.org/pantsbuild/pants/builds/85625910

Bugs closed: 1905, 2374

Reviewed at https://rbcommons.com/s/twitter/r/2971/

contrib/cpp/src/python/pants/contrib/cpp/tasks/cpp_task.py

@@ -45,8 +45,6 @@ def run_command(self, cmd, workunit):
       subprocess.check_call(cmd, stdout=workunit.output('stdout'), stderr=workunit.output('stderr'))
     except subprocess.CalledProcessError as e:
       raise TaskError('Execution failed: {0}'.format(e))
-    except:
-      raise TaskError('Failed to execute {0}'.format(cmd))
 
   @property
   def cpp_toolchain(self):

pants.ini

@@ -136,9 +136,6 @@ skip: True
 [pycheck-context-manager]
 skip: True
 
-[pycheck-except-statement]
-skip: True
-
 
 [compile.zinc]
 worker_count: 4

src/python/pants/goal/run_tracker.py

@@ -200,19 +200,19 @@ def new_workunit_under_parent(self, name, parent, labels=None, cmd='', log_confi
     workunit = WorkUnit(run_info_dir=self.run_info_dir, parent=parent, name=name, labels=labels,
                         cmd=cmd, log_config=log_config)
     workunit.start()
+
+    outcome = WorkUnit.FAILURE  # Default to failure we will override if we get success/abort.
     try:
       self.report.start_workunit(workunit)
       yield workunit
     except KeyboardInterrupt:
-      workunit.set_outcome(WorkUnit.ABORTED)
+      outcome = WorkUnit.ABORTED
       self._aborted = True
       raise
-    except:
-      workunit.set_outcome(WorkUnit.FAILURE)
-      raise
     else:
-      workunit.set_outcome(WorkUnit.SUCCESS)
+      outcome = WorkUnit.SUCCESS
     finally:
+      workunit.set_outcome(outcome)
       self.end_workunit(workunit)
 
   def log(self, level, *msg_elements):