use invite token instead of id for invitation url

alembic/versions/81e6babf5136_add_token_to_invitation.py

@@ -0,0 +1,30 @@
+"""add token to invitation
+
+Revision ID: 81e6babf5136
+Revises: 67955a4abaef
+Create Date: 2018-10-29 09:26:30.728348
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '81e6babf5136'
+down_revision = '67955a4abaef'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('invitations', sa.Column('token', sa.String(), nullable=True))
+    op.create_index(op.f('ix_invitations_token'), 'invitations', ['token'], unique=True)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_invitations_token'), table_name='invitations')
+    op.drop_column('invitations', 'token')
+    # ### end Alembic commands ###