Adds protobuf conda env for readthedocs

.readthedocs.yaml

@@ -23,3 +23,7 @@ python:
 # We do not require git submodules to process this
 submodules:
   exclude: all
+
+# The conda env will bring along protobuf
+conda:
+  environment: docs/environment.yml

docs/environment.yml

@@ -0,0 +1,57 @@
+name: agatha_readthedocs
+channels:
+  - defaults
+dependencies:
+  - _libgcc_mutex=0.1=main
+  - ca-certificates=2020.1.1=0
+  - certifi=2020.4.5.1=py38_0
+  - ld_impl_linux-64=2.33.1=h53a641e_7
+  - libedit=3.1.20181209=hc058e9b_0
+  - libffi=3.2.1=hd88cf55_4
+  - libgcc-ng=9.1.0=hdf63c60_0
+  - libprotobuf=3.11.4=hd408876_0
+  - libstdcxx-ng=9.1.0=hdf63c60_0
+  - ncurses=6.2=he6710b0_1
+  - openssl=1.1.1g=h7b6447c_0
+  - pip=20.0.2=py38_1
+  - protobuf=3.11.4=py38he6710b0_0
+  - python=3.8.2=hcf32534_0
+  - readline=8.0=h7b6447c_0
+  - setuptools=46.1.3=py38_0
+  - six=1.14.0=py38_0
+  - sqlite=3.31.1=h62c20be_1
+  - tk=8.6.8=hbc83047_0
+  - wheel=0.34.2=py38_0
+  - xz=5.2.5=h7b6447c_0
+  - zlib=1.2.11=h7b6447c_3
+  - pip:
+    - alabaster==0.7.12
+    - babel==2.8.0
+    - chardet==3.0.4
+    - commonmark==0.9.1
+    - docutils==0.16
+    - idna==2.9
+    - imagesize==1.2.0
+    - jinja2==2.11.2
+    - markupsafe==1.1.1
+    - packaging==20.3
+    - pbr==5.4.5
+    - pygments==2.6.1
+    - pyparsing==2.4.7
+    - pytz==2020.1
+    - recommonmark==0.6.0
+    - requests==2.23.0
+    - snowballstemmer==2.0.0
+    - sphinx==3.0.3
+    - sphinx-autodoc-typehints==1.10.3
+    - sphinx-rtd-theme==0.4.3
+    - sphinxcontrib-apidoc==0.3.0
+    - sphinxcontrib-applehelp==1.0.2
+    - sphinxcontrib-devhelp==1.0.2
+    - sphinxcontrib-htmlhelp==1.0.3
+    - sphinxcontrib-jsmath==1.0.1
+    - sphinxcontrib-qthelp==1.0.3
+    - sphinxcontrib-serializinghtml==1.1.4
+    - urllib3==1.25.9
+prefix: /home/jsybran/anaconda3/envs/agatha_readthedocs
+