(build) Update AppVeyor config file

Mainly to allow the building of hotfix branches, which isn't currently
allowed.

Author: gep13

.appveyor.yml

@@ -10,9 +10,22 @@ image: Visual Studio 2019
 build_script:
     - ps: .\build.ps1 -Target ContinuousIntegration
 
+#---------------------------------#
 # Tests
+#---------------------------------#
 test: off
 
+#---------------------------------#
+#  Pull Requests                  #
+#---------------------------------#
+pull_requests:
+  do_not_increment_build_number: true
+
+#---------------------------------#
+#  General                        #
+#---------------------------------#
+skip_branch_with_pr: true
+
 #---------------------------------#
 #        Branches to build        #
 #---------------------------------#
@@ -21,6 +34,8 @@ branches:
     only:
         - develop
         - master
+        - /release\/.*/
+        - /hotfix\/.*/
 
 #---------------------------------#
 #  Build Cache                    #