fix: Work around failure to launch Edge on Linux (#32)

Work around MicrosoftEdge/EdgeWebDriver#102,
in which Linux versions of msedgedriver launch Chrome instead of Edge
starting with version 115. For now, driver version 114 is working for
Edge 115 on Linux.

This does not appear to affect other platforms.

edge.js

@@ -63,8 +63,6 @@ class EdgeWebDriverInstaller extends WebDriverInstallerBase {
    * @return {!Promise<string>}
    */
   async getBestDriverVersion(browserVersion) {
-    const idealMajorVersion = parseInt(browserVersion.split('.')[0], 10);
-
     let platform;
     if (os.platform() == 'linux') {
       platform = 'LINUX';
@@ -80,6 +78,18 @@ class EdgeWebDriverInstaller extends WebDriverInstallerBase {
       return `${CDN_URL}/LATEST_RELEASE_${majorVersion}_${platform}`;
     };
 
+    let idealMajorVersion = parseInt(browserVersion.split('.')[0], 10);
+
+    // Work around https://github.com/MicrosoftEdge/EdgeWebDriver/issues/102,
+    // in which Linux versions of msedgedriver launch Chrome instead of Edge
+    // starting with version 115.  For now, driver version 114 is working for
+    // Edge 115 on Linux.
+    if (os.platform() == 'linux') {
+      if (idealMajorVersion > 114) {
+        idealMajorVersion = 114;
+      }
+    }
+
     return await InstallerUtils.fetchVersionUrlWithAutomaticDowngrade(
         idealMajorVersion,
         /* minMajorVersion */ idealMajorVersion - 2,