Update pyproj version number

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "sondehub"
-version = "0.3.0"
+version = "0.3.1"
 description = "SDK to access SondeHub open data, and helpers for uploading telemetry."
 authors = ["Michaela <git@michaela.lgbt>"]
 readme = "README.md"
@@ -23,4 +23,4 @@ requires = ["poetry-core>=1.0.0"]
 build-backend = "poetry.core.masonry.api"
 
 [tool.poetry.scripts]
-sondehub = 'sondehub:__main__.main'
+sondehub = 'sondehub:__main__.main'