fix rtd build

docs/conf.py

@@ -55,19 +55,17 @@
 project = "Towncrier"
 copyright = "{}, Towncrier contributors. Ver {}".format(
     _today.year,
-    towncrier_version.public(),
+    towncrier_version,
 )
 author = "Amber Brown"
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the
 # built documents.
 # The short X.Y version.
-version = "{}.{}.{}".format(
-    towncrier_version.major, towncrier_version.minor, towncrier_version.micro
-)
+version = ".".join(towncrier_version.split(".")[:3])
 # The full version, including alpha/beta/rc tags.
-release = towncrier_version.public()
+release = towncrier_version
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.