Import licenses from SPDX

Fixes #326

app/models/packages.py

@@ -35,10 +35,12 @@ class License(db.Model):
 	id      = db.Column(db.Integer, primary_key=True)
 	name    = db.Column(db.String(50), nullable=False, unique=True)
 	is_foss = db.Column(db.Boolean,    nullable=False, default=True)
+	url     = db.Column(db.String(128), nullable=True, default=None)
 
-	def __init__(self, v, is_foss=True):
+	def __init__(self, v: str, is_foss: bool = True, url: str = None):
 		self.name = v
 		self.is_foss = is_foss
+		self.url = url
 
 	def __str__(self):
 		return self.name