fix: fix unescaped special chararacter in regex

- BUG: The unescaped period functions as a wildcard character instead of a plain dot as intended.
- Inside a string or template literal, a period preceded by a single backslash (escape sequence) will be parsed as an unescaped period.
- The string representation of \. is the double-escaped literal "\\."

see also: issue oslabs-beta#85

sapling/src/SaplingParser.ts

@@ -187,7 +187,7 @@ export class SaplingParser {
     if (!ext) {
       // Try and find file extension that exists in directory:
       const fileArray = fs.readdirSync(path.dirname(componentTree.filePath));
-      const regEx = new RegExp(`${componentTree.fileName}.(j|t)sx?$`);
+      const regEx = new RegExp(`${componentTree.fileName}\\.(j|t)sx?$`);
       fileName = fileArray.find(fileStr => fileStr.match(regEx));
       fileName ? componentTree.filePath += path.extname(fileName) : null;
     }