(build) Update AppVeyor Configuration

Author: gep13

.appveyor.yml

@@ -9,9 +9,22 @@ image: Visual Studio 2017
 build_script:
   - ps: .\build.ps1 -Target AppVeyor
 
+#---------------------------------#
 # Tests
+#---------------------------------#
 test: off
 
+#---------------------------------#
+#  Pull Requests                  #
+#---------------------------------#
+pull_requests:
+  do_not_increment_build_number: true
+
+#---------------------------------#
+#  General                        #
+#---------------------------------#
+skip_branch_with_pr: true
+
 #---------------------------------#
 #        Branches to build        #
 #---------------------------------#
@@ -27,5 +40,11 @@ branches:
 #  Build Cache                    #
 #---------------------------------#
 cache:
-- Source\packages -> Source\**\packages.config
-- tools -> recipe.cake
+- tools -> recipe.cake, tools/packages.config
+
+#---------------------------------#
+#  Skip builds for doc changes    #
+#---------------------------------#
+skip_commits:
+  # Regex for matching commit message
+  message: /(doc).*/