add Term SQLAlchemy ORM model

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

aurweb/models/term.py

+from sqlalchemy.orm import mapper
+
+from aurweb.schema import Terms
+
+
+class Term:
+    def __init__(self,
+                 Description: str = None, URL: str = None,
+                 Revision: int = None):
+        self.Description = Description
+        self.URL = URL
+        self.Revision = Revision
+
+
+mapper(Term, Terms)

test/test_term.py

+import pytest
+
+from sqlalchemy.exc import IntegrityError
+
+from aurweb.db import create, delete
+from aurweb.models.term import Term
+
+
+def test_term_creation():
+    term = create(Term, Description="Term description",
+                  URL="https://fake_url.io")
+    assert bool(term.ID)
+    assert term.Description == "Term description"
+    assert term.URL == "https://fake_url.io"
+    assert term.Revision == 1
+    delete(Term, Term.ID == term.ID)
+
+
+def test_term_null_description_raises_exception():
+    from aurweb.db import session
+    with pytest.raises(IntegrityError):
+        create(Term, URL="https://fake_url.io")
+    session.rollback()
+
+
+def test_term_null_url_raises_exception():
+    from aurweb.db import session
+    with pytest.raises(IntegrityError):
+        create(Term, Description="Term description")
+    session.rollback()