add PackageDependency (PackageDepends) ORM model

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/models/package_dependency.py

@@ -0,0 +1,31 @@
+from sqlalchemy.orm import mapper
+
+from aurweb.db import make_relationship
+from aurweb.models.dependency_type import DependencyType
+from aurweb.models.package import Package
+from aurweb.schema import PackageDepends
+
+
+class PackageDependency:
+    def __init__(self, Package: Package = None,
+                 DependencyType: DependencyType = None,
+                 DepName: str = None, DepDesc: str = None,
+                 DepCondition: str = None, DepArch: str = None):
+        self.Package = Package
+        self.DependencyType = DependencyType
+        self.DepName = DepName  # nullable=False
+        self.DepDesc = DepDesc
+        self.DepCondition = DepCondition
+        self.DepArch = DepArch
+
+
+properties = {
+    "Package": make_relationship(Package, PackageDepends.c.PackageID,
+                                 "package_dependencies"),
+    "DependencyType": make_relationship(DependencyType,
+                                        PackageDepends.c.DepTypeID,
+                                        "package_dependencies")
+}
+
+mapper(PackageDependency, PackageDepends, properties=properties,
+       primary_key=[PackageDepends.c.PackageID, PackageDepends.c.DepTypeID])