Start large refactoring of tests and project structure

* Put tests in tests/ diretory
* Write functional tests
* Create setup.py
* Put sources into django_migration_linter folder (for future PyPi publishing)

tests/fixtures.py

@@ -0,0 +1,40 @@
+# Copyright 2017 3YOURMIND GmbH
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+# http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+
+_BASE_DIR = os.path.join(
+    os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
+    'tests/')
+_FIXTURES_FOLDER = os.path.join(_BASE_DIR, 'test_project_fixtures/')
+
+ADD_NOT_NULL_COLUMN_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_project_add_not_null_column/')
+CREATE_TABLE_WITH_NOT_NULL_COLUMN_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_project_create_table_with_not_null_column/')
+DROP_COLUMN_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_project_drop_column/')
+RENAME_COLUMN_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_project_rename_column/')
+RENAME_TABLE_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_project_rename_table/')
+ADD_NOT_NULL_COLUMN_FOLLOWED_BY_DEFAULT_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_project_add_not_null_column_followed_by_default/')
+MULTI_COMMIT_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_project_multi_commit/')
+
+NOT_DJANGO_GIT_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_git_project/')
+NOT_GIT_DJANGO_PROJECT = os.path.join(
+    _FIXTURES_FOLDER, 'test_django_without_git_project/')