title: Cannot run source activate with conda in Fish-shell
body: <p>I follow <a href="https://github.com/conda/conda/pull/545#issuecomment-224833788" rel="noreferrer">conda_PR_545</a>, <a href="https://github.com/conda/conda/issues/4221#issuecomment-271343621" rel="noreferrer">conda issues 4221</a> and still not working on Ubuntu.</p>
  
  <p>After downloading conda.fish from <a href="https://gist.github.com/jiffyclub/9679788" rel="noreferrer">here</a>, and mv it to anaconda3/bin/.</p>
  
  <p>Add "source /home/phejimlin/anaconda3/bin/conda.fish" at the end of ~/.config/fish/config.fish.</p>
  
  <pre><code>conda activate spark_env
  Traceback (most recent call last):
  File "/home/phejimlin/anaconda3/bin/conda", line 6, in 
  sys.exit(conda.cli.main())
  File "/home/phejimlin/anaconda3/lib/python3.6/site-packages/conda/cli/main.py", line 161, in main
  raise CommandNotFoundError(argv1, message)
  TypeError: init() takes 2 positional arguments but 3 were given
  </code></pre>
  
  <p>or</p>
  
  <pre><code>activate spark_env
  Error: activate must be sourced. Run 'source activate envname'
  instead of 'activate envname'.
  </code></pre>
  
  <p>Do I miss something?</p>