DOC: Switch ipynb links to nbviewer + Q2 --verbose

We can reasonably use --verbose in the Q2 examples now that biocore#95 stuff
is sorted out. (Using --verbose in q2-qurro should be equivalent to
the default invocation of standalone Qurro.)

[ci skip]

README.md

@@ -87,9 +87,9 @@ available in the QIIME 2 plugin version of Qurro.
 Examples of using Qurro (both inside and outside of QIIME 2) are
 available in Qurro's example Jupyter notebooks, which are located
 [here](https://github.com/biocore/qurro/tree/master/example_notebooks):
-- [**`deicode_example.ipynb`**](https://github.com/biocore/qurro/blob/master/example_notebooks/DEICODE_sleep_apnea/deicode_example.ipynb)
+- [**`deicode_example.ipynb`**](https://nbviewer.jupyter.org/github/biocore/qurro/blob/master/example_notebooks/DEICODE_sleep_apnea/deicode_example.ipynb)
   demonstrates using [DEICODE](https://github.com/biocore/DEICODE) and then using Qurro to visualize DEICODE's output.
-- [**`songbird_example.ipynb`**](https://github.com/biocore/qurro/blob/master/example_notebooks/songbird_red_sea/songbird_example.ipynb)
+- [**`songbird_example.ipynb`**](https://nbviewer.jupyter.org/github/biocore/qurro/blob/master/example_notebooks/songbird_red_sea/songbird_example.ipynb)
   demonstrates using [songbird](https://github.com/biocore/songbird) and then using Qurro to visualize songbird's output.
 
 #### "Moving Pictures" Tutorial

example_notebooks/DEICODE_sleep_apnea/deicode_example.ipynb

@@ -222,6 +222,8 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
+      "689 feature(s) in the BIOM table were not present in the feature rankings.\r\n",
+      "These feature(s) have been removed from the visualization.\r\n",
       "\u001b[32mSaved Visualization to: output/qurro_plot_q2.qzv\u001b[0m\r\n"
      ]
     }
@@ -232,6 +234,7 @@
     "    --i-table output/qiita_10422_table.biom.qza \\\n",
     "    --m-sample-metadata-file input/qiita_10422_metadata.tsv \\\n",
     "    --m-feature-metadata-file input/taxonomy.tsv \\\n",
+    "    --verbose \\\n",
     "    --o-visualization output/qurro_plot_q2.qzv"
    ]
   },

example_notebooks/songbird_red_sea/songbird_example.ipynb

@@ -200,6 +200,7 @@
     "    --i-table output/redsea.biom.qza \\\n",
     "    --m-sample-metadata-file input/redsea_metadata.txt \\\n",
     "    --m-feature-metadata-file input/feature_metadata.txt \\\n",
+    "    --verbose \\\n",
     "    --o-visualization output/qurro_plot_q2.qzv"
    ]
   },
@@ -251,7 +252,7 @@
       "WARNING:tensorflow:From /anaconda3/envs/qiime2-2019.4/lib/python3.6/site-packages/tensorflow/python/ops/math_ops.py:3066: to_int32 (from tensorflow.python.ops.math_ops) is deprecated and will be removed in a future version.\r\n",
       "Instructions for updating:\r\n",
       "Use tf.cast instead.\r\n",
-      "100%|█████████████████████████████████████| 8000/8000 [00:05<00:00, 1367.36it/s]\r\n"
+      "100%|█████████████████████████████████████| 8000/8000 [00:06<00:00, 1293.86it/s]\r\n"
      ]
     }
    ],