gitignore: Add temporary SQLite files (iterative#1322)

Fix iterative#1319

.dvc/.gitignore

@@ -5,4 +5,6 @@ config.local
 updater
 cache
 state
-state.lock
+state.lock
+state-journal
+state-wal

dvc/project.py

@@ -131,10 +131,12 @@ def destroy(self):
         shutil.rmtree(self.dvc_dir)
 
     def _ignore(self):
-        flist = [self.state.state_file,
-                 self.lock.lock_file,
-                 self.config.config_local_file,
-                 self.updater.updater_file]
+        flist = [
+            self.state.state_file,
+            self.lock.lock_file,
+            self.config.config_local_file,
+            self.updater.updater_file,
+        ] + self.state.temp_files
 
         if self.cache.local.cache_dir.startswith(self.root_dir):
             flist += [self.cache.local.cache_dir]

dvc/state.py

@@ -57,6 +57,13 @@ def __init__(self, project, config):
             return
 
         self.state_file = os.path.join(self.dvc_dir, self.STATE_FILE)
+
+        # https://www.sqlite.org/tempfiles.html
+        self.temp_files = [
+            self.state_file + '-journal',
+            self.state_file + '-wal',
+        ]
+
         self.db = None
         self.c = None
         self.inserts = 0