title: Wildcards in input and output not working
body: <p>I added a rule <code>get_timezone_periods</code> with wildcards in the input and output but is not working with error <code>Missing input files for rule all</code></p>
  
  <p>Manual typing the paths works</p>
  
  <pre><code>"data/raw/test1/ros/timezone.csv",
  "data/raw/test3/t02/timezone.csv"
  </code></pre>
  
  <p>Using wildcards does not</p>
  
  <pre><code>"data/raw/{{db}}/{{user}}/timezone.csv"
  </code></pre>
  
  <p>My code:</p>
  
  <pre class="lang-py prettyprint-override"><code>SENSORS=["timezone", "touch"]
  DBS_USERS={"test1":["ros"],
              "test3":["t02"]}
  
  def db_user_path(paths):
      new_paths = []
      for db, users in DBS_USERS.items():
          for user in users:
              for path in paths:
                  new_paths.append(path.replace("db/", db + "/").replace("user/", user+ "/"))
      return new_paths
  
  rule all:
      input:
          sensors = db_user_path(expand("data/raw/db/user/{sensor}.csv", sensor=SENSORS)),
          timezone_periods = db_user_path(["data/processed/db/user/timezone_periods.csv"])
  
  rule download_dataset:
      input:
          "data/external/{db}-{user}.participant"
      output:
          expand("data/raw/{{db}}/{{user}}/{sensor}.csv", sensor=SENSORS)
      script:
          "src/data/download_dataset.R"
  
  
  rule get_timezone_periods:
      input:
          # This line below does not work
          # "data/raw/{{db}}/{{user}}/timezone.csv"
          # These two lines work
          "data/raw/test1/ros/timezone.csv",
          "data/raw/test3/t02/timezone.csv"
      output:
          # This line below does not work
          # "data/processed/{{db}}/{{user}}/timezone_periods.csv"
          # These two lines work
          "data/processed/test1/ros/timezone_periods.csv",
          "data/processed/test3/t02/timezone_periods.csv"
      script:
          "src/data/get_timezone_periods.R"
  </code></pre>