Let's not build libsass as default

(hopefully doesn't break in production)

Pipfile

@@ -7,6 +7,7 @@ verify_ssl = true
 pylint = "*"
 pylint-flask-sqlalchemy = "*"
 rope = "*"
+libsass = "*"
 
 [packages]
 flask = "*"
@@ -19,7 +20,6 @@ flask-login = "*"
 flask-wtf = "*"
 flask-assets = "*"
 # pyscss = "*"
-libsass = "*"
 cssmin = "*"
 # python-magic = "*"
 # flask-mail = "*"