Add missing log to Java version check (apache#624)

* Add missing log to Java version check
* Simplify version check output

Resolves apache#623

bin/templates/cordova/lib/check_reqs.js

@@ -355,15 +355,18 @@ module.exports.check_android_target = function (originalError) {
 // Returns a promise.
 module.exports.run = function () {
     return Q.all([this.check_java(), this.check_android()]).then(function (values) {
+        console.log('Checking Java JDK and Android SDK versions');
         console.log('ANDROID_HOME=' + process.env['ANDROID_HOME']);
-        console.log('JAVA_HOME=' + process.env['JAVA_HOME']);
 
         if (!String(values[0]).startsWith('1.8.')) {
-            throw new CordovaError(`Requirements check failed for JDK 8 ('1.8.*')`);
+            throw new CordovaError(
+                'Requirements check failed for JDK 8 (\'1.8.*\')! Detected version: ' + values[0] + '\n' +
+                'Check your JAVA_HOME / ANDROID_HOME / PATH environment variables.'
+            );
         }
 
         if (!values[1]) {
-            throw new CordovaError('Requirements check failed for Android SDK');
+            throw new CordovaError('Requirements check failed for Android SDK! Android SDK was not detected.');
         }
     });
 };