refactor: Use easier to understand functions and variable names

The old naming led to me breaking the code when I wanted to refactor it.
"hasOnlyAllowedPackages" could be easily interpreted as "contains no
license not in the allow list", which is not what the function does.

lib/index.js

@@ -536,17 +536,24 @@ exports.init = function init(args, callback) {
             }
         };
 
+        /**
+         * Check if the current license contains (eventually among others) at least one of the allowed licenses
+         *
+         * @param      {string}  currentLicense  The current license
+         * @param      {<type>}  packageName     The package name
+         */
         const checkForOnlyAllow = (currentLicense, packageName) => {
             if (toCheckforOnlyAllow.length > 0) {
-                let hasOnlyAllowedPackages = false;
+                let containsOneOfAllowedPackages = false;
 
-                toCheckforOnlyAllow.forEach((allowedLicense) => {
-                    if (currentLicense.indexOf(allowedLicense) >= 0) {
-                        hasOnlyAllowedPackages = true;
+                for (const allowedLicense of toCheckforOnlyAllow) {
+                    if (currentLicense.includes(allowedLicense)) {
+                        containsOneOfAllowedPackages = true;
+                        break;
                     }
-                });
+                }
 
-                if (!hasOnlyAllowedPackages) {
+                if (!containsOneOfAllowedPackages) {
                     console.error(
                         `Package "${packageName}" is licensed under "${currentLicense}" which is not permitted by the --onlyAllow flag. Exiting.`,
                     );