Add email_import in the modules loaded by default

.travis.yml

@@ -3,6 +3,8 @@ language: python
 services:
     - redis-server
 
+cache: pip
+
 python:
     - "3.3"
     - "3.4"

misp_modules/modules/import_mod/__init__.py

@@ -1,3 +1,3 @@
 from . import _vmray
 
-__all__ = ['vmray_import', 'testimport', 'ocr', 'stiximport', 'cuckooimport']
+__all__ = ['vmray_import', 'testimport', 'ocr', 'stiximport', 'cuckooimport', 'email_import']