Lock packages python dependencies to their current major version

- This may help reproduce test failures seen on Github locally
- Interfaces shouldn't break within bounds of minor version updates of
  dependent packages, assuming their following semantic versioning

environment.yml

@@ -3,13 +3,13 @@ channels:
   - conda-forge
 dependencies:
   - python=3.*
-  - numpy=1.21.*
+  - numpy=1.*
-  - pytorch
+  - pytorch=1.*
-  - transformers
+  - transformers=4.*
-  - sentence-transformers
+  - sentence-transformers=2.0.0
-  - fastapi
+  - fastapi=0.*
-  - uvicorn
+  - uvicorn=0.*
-  - pyyaml
+  - pyyaml=5.*
-  - pytest
+  - pytest=6.*
-  - pillow
+  - pillow=8.*
-  - torchvision
+  - torchvision=0.*