Added version String to lbmpy

.gitignore

@@ -14,3 +14,4 @@ _local_tmp
 /lbmpy_tests/db
 doc/bibtex.json
 /html_doc
+RELEASE-VERSION

lbmpy/__init__.py

+def _get_release_file():
+    import os.path
+    file_path = os.path.abspath(os.path.dirname(__file__))
+    return os.path.join(file_path, '..', 'RELEASE-VERSION')
+
+
+try:
+    __version__ = open(_get_release_file(), 'r').read()
+except IOError:
+    __version__ = 'development'

lbmpy_tests/test_version_string.py

+import pystencils as ps
+from pathlib import Path
+
+def test_version_string():
+    file_path = Path(__file__).parent
+    release_version = file_path.parent.absolute() / 'RELEASE-VERSION'
+    if release_version.exists ():
+        with open(release_version, "r") as f:
+            version = f.read()
+        assert ps.__version__ == version
+    else:
+        assert ps.__version__ == "development"