Update archive script to try 7z on PATH

If the Program Files folder is not found. This is useful for AppVeyor,
which does not document where 7zip is installed but has it in its PATH
variable

scripts/archive.js

@@ -25,11 +25,9 @@ function getGitDescription() {
 }
 
 function compress(sourcePath, destPath) {
-  let sevenzipPath = '';
-  if (os.platform() === 'win32') {
-    sevenzipPath = path.join('C:\\', 'Program Files', '7-Zip', '7z.exe');
-  } else {
-    sevenzipPath = '/usr/bin/7z';
+  let sevenzipPath = path.join('C:\\', 'Program Files', '7-Zip', '7z.exe');
+  if (os.platform() !== 'win32' || !helpers.fileExists(sevenzipPath)) {
+    sevenzipPath = '7z';
   }
 
   // First remove any existing archive.
@@ -176,6 +174,14 @@ function createApiArchive(rootPath, binaryPath, tempPath, destPath) {
   fs.removeSync(tempPath);
 }
 
+function getFilenameSuffix(releasePath, gitDescription) {
+  if (releasePath.label) {
+    return `${gitDescription} (${releasePath.label}).7z`;
+  }
+
+  return `${gitDescription}.7z`;
+}
+
 let rootPath = '.';
 if (process.argv.length > 2) {
   rootPath = process.argv[2];
@@ -185,25 +191,18 @@ const tempPath = path.join(rootPath, 'build', 'archive.tmp');
 const gitDesc = getGitDescription();
 vulcanize(rootPath);
 
-const releasePaths = helpers.getAppReleasePaths(rootPath);
-for (let i = 0; i < releasePaths.length; ++i) {
-  if (releasePaths[i].label) {
-    const filename = `LOOT ${gitDesc} (${releasePaths[i].label}).7z`;
-    createAppArchive(rootPath,
-                     releasePaths[i].path,
-                     tempPath,
-                     path.join(rootPath, 'build', filename));
-  } else {
-    createAppArchive(releasePaths[i].path,
-                     path.join(rootPath, 'build', `LOOT ${gitDesc}.7z`));
-  }
-}
-
-const binaryPaths = helpers.getApiBinaryPaths(rootPath);
-for (let i = 0; i < binaryPaths.length; ++i) {
-  const filename = `LOOT API ${gitDesc} (${binaryPaths[i].label}).7z`;
-  createApiArchive(rootPath,
-                   binaryPaths[i].path,
+helpers.getAppReleasePaths(rootPath).forEach(releasePath => {
+  const filename = `LOOT ${getFilenameSuffix(releasePath, gitDesc)}`;
+  createAppArchive(rootPath,
+                   releasePath.path,
                    tempPath,
                    path.join(rootPath, 'build', filename));
-}
+});
+
+helpers.getApiBinaryPaths(rootPath).forEach(releasePath => {
+  const filename = `LOOT API ${getFilenameSuffix(releasePath, gitDesc)}`
+  createApiArchive(rootPath,
+                   releasePath.path,
+                   tempPath,
+                   path.join(rootPath, 'build', filename));
+});