Return the exitcode again

Fixes #543.

coala

@@ -13,7 +13,9 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import sys
+
 from coalib.coala import main
 
 if __name__ == "__main__":
-    main()
+    sys.exit(main())

coala.py

@@ -13,7 +13,9 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import sys
+
 from coalib.coala import main
 
 if __name__ == "__main__":
-    main()
+    sys.exit(main())

coalib/coala.py

@@ -75,8 +75,8 @@ def main():
     if interactor is not None and isinstance(interactor, ClosableObject):
         interactor.close()
 
-    exit(exitcode)
+    return exitcode
 
 
 if __name__ == "__main__":
-    main()
+    sys.exit(main())