relax library versions for doc

docs/requirements.txt

@@ -1,36 +1,36 @@
-recommonmark==0.7.1
-Sphinx==4.1.2
-sphinx-autobuild==2021.3.14
-sphinx-copybutton==0.4.0
-sphinx-markdown-tables==0.0.15
-sphinx-rtd-theme==0.5.2
-sphinxcontrib-applehelp==1.0.2
-sphinxcontrib-devhelp==1.0.2
-sphinxcontrib-htmlhelp==2.0.0
-sphinxcontrib-jsmath==1.0.1
-sphinxcontrib-qthelp==1.0.3
-sphinxcontrib-serializinghtml==1.1.5
-nbclient==0.5.4
-nbconvert==6.1.0
-nbformat==5.1.3
-nbsphinx==0.8.7
-widgetsnbextension==3.5.1
-ipykernel==6.4.1
-ipython==7.27.0
-ipython-genutils==0.2.0
-ipywidgets==7.6.4
-scipy==1.7.1
-tensorboard==2.6.0
-tensorboard-data-server==0.6.1
-tensorboard-plugin-wit==1.8.0
-tensorboardX==2.4
-tensorflow==2.5.0
-tensorflow-estimator==2.5.0
-tensorflow-hub==0.12.0
-tensorflow-text==2.5.0
-sentence-transformers==2.0.0
-transformers==4.10.1
-textattack==0.3.4
-sqlitedict==1.7.0
-stanza==1.2.3
-Cython==0.29.24
+recommonmark
+Sphinx
+sphinx-autobuild
+sphinx-copybutton
+sphinx-markdown-tables
+sphinx-rtd-theme
+sphinxcontrib-applehelp
+sphinxcontrib-devhelp
+sphinxcontrib-htmlhelp
+sphinxcontrib-jsmath
+sphinxcontrib-qthelp
+sphinxcontrib-serializinghtml
+nbclient
+nbconvert
+nbformat
+nbsphinx
+widgetsnbextension
+ipykernel
+ipython
+ipython-genutils
+ipywidgets
+scipy
+tensorboard
+tensorboard-data-server
+tensorboard-plugin-wit
+tensorboardX
+tensorflow
+tensorflow-estimator
+tensorflow-hub
+tensorflow-text
+sentence-transformers
+transformers
+textattack
+sqlitedict
+stanza
+Cython