Always build installer on AppVeyor

So that issues are discovered more quickly. Don't cache the Inno Setup
directory to keep things simple.

appveyor.yml

@@ -9,7 +9,6 @@ cache:
   - bower_components
   - C:\projects\boost_1_61_0\boost
   - C:\projects\boost_1_61_0\stage\lib
-  - C:\Program Files (x86)\Inno Setup 5
 
 environment:
   access_token:
@@ -18,7 +17,7 @@ environment:
     secure: u234T2688DZmz4JH5+0iAHcUcL2fEIGculb8655bn4B1q7GckhplsitzgEbv3NFc
 
 install:
-  - choco install doxygen.portable
+  - choco install -y doxygen.portable InnoSetup
   - python -m pip install sphinx breathe sphinx_rtd_theme
   - npm install
   - .\node_modules\.bin\bower install
@@ -45,8 +44,6 @@ after_test:
   - set PATH=%PATH%;C:\cygwin\bin\
   - node scripts\potomo.js
   - node scripts\archive.js
-  # AppVeyor checks out a specific commit, but that means the archive script
-  # can't tell which branch it's on, so rename the 7z archives.
   - ps: $env:GIT_DESCRIBE = ((git describe --tags --long) | Out-String) -replace "`n|`r", ""
   - ps: scripts\appveyor\build_installer.ps1
 

scripts/appveyor/build_installer.ps1

@@ -7,22 +7,16 @@ function DownloadLanguageFile($languageFile, $innoPath) {
 
 $innoInstallPath = 'C:\Program Files (x86)\Inno Setup 5'
 
-if ($env:APPVEYOR_REPO_TAG -eq 'true') {
-  if (!(Test-Path $innoInstallPath)) {
-    choco install -y InnoSetup
+# Install the Inno Download Plugin
+$url = 'https://bitbucket.org/mitrich_k/inno-download-plugin/downloads/idpsetup-1.5.1.exe'
+(New-Object System.Net.WebClient).DownloadFile($url, (pwd).path + '/idpsetup-1.5.1.exe')
+./idpsetup-1.5.1.exe /verysilent
 
-    # Install the Inno Download Plugin
-    $url = 'https://bitbucket.org/mitrich_k/inno-download-plugin/downloads/idpsetup-1.5.1.exe'
-    (New-Object System.Net.WebClient).DownloadFile($url, (pwd).path + '/idpsetup-1.5.1.exe')
-    ./idpsetup-1.5.1.exe /verysilent
+# Also install the unofficial Korean and Simplified Chinese translation
+# files for Inno Setup.
+DownloadLanguageFile '\Korean.isl'  $innoInstallPath
+DownloadLanguageFile '\ChineseSimplified.isl'  $innoInstallPath
 
-    # Also install the unofficial Korean and Simplified Chinese translation
-    # files for Inno Setup.
-    DownloadLanguageFile '\Korean.isl'  $innoInstallPath
-    DownloadLanguageFile '\ChineseSimplified.isl'  $innoInstallPath
-  }
+$env:PATH += ';' + $innoInstallPath
 
-  $env:PATH += ';' + $innoInstallPath
-
-  iscc scripts\installer.iss
-}
+iscc scripts\installer.iss