Replace outdated mustache library (#307)

* Change mustache library to Pystache

* Remove unneeded import

mycroft/dialog/__init__.py

@@ -16,7 +16,7 @@
 # along with Mycroft Core.  If not, see <http://www.gnu.org/licenses/>.
 
 
-import mustache
+import pystache
 import os
 import random
 from mycroft.util import log
@@ -78,7 +78,7 @@ class MustacheDialogRenderer(object):
             index = random.randrange(len(template_functions))
         else:
             index %= len(template_functions)
-        return mustache.render(template_functions[index], context)
+        return pystache.render(template_functions[index], context)
 
 
 class DialogLoader(object):

requirements.txt

@@ -1,5 +1,5 @@
 shortuuid==0.4.3
-mustache==0.1.4
+pystache==0.5.4
 configobj==5.0.6
 wikipedia==1.4.0
 requests==2.8.1