Fix broken regex for Dockerfile parsing

tools/reparsedockerfile.py

@@ -0,0 +1,18 @@
+from util.dockerfileparse import parse_dockerfile, ParsedDockerfile, serialize_dockerfile
+
+with open('Dockerfile.test', 'r') as dockerfileobj:
+  parsed_dockerfile = parse_dockerfile(dockerfileobj.read())
+
+quay_reponame = 'something'
+env_command = {
+  'command': 'ENV',
+  'parameters': 'QUAY_REPOSITORY %s' % quay_reponame
+}
+
+for index, command in reversed(list(enumerate(parsed_dockerfile.commands))):
+  if command['command'] == 'FROM':
+    new_command_index = index + 1
+    parsed_dockerfile.commands.insert(new_command_index, env_command)
+    break
+
+print serialize_dockerfile(parsed_dockerfile)

util/dockerfileparse.py

@@ -1,6 +1,6 @@
 import re
 
-LINE_CONTINUATION_REGEX = re.compile('\s*\\\s*\n')
+LINE_CONTINUATION_REGEX = re.compile(r'(\s)*\\(\s)*\n')
 COMMAND_REGEX = re.compile('([A-Za-z]+)\s(.*)')
 
 COMMENT_CHARACTER = '#'