fix(mapping): Fix mapping again in editors

Put back the original fix introduced in 0da3f7d. During the refactor of the
mapping function, this code disappeared.
Would be great to have some tests testing this specific case as well.

src/index.js

@@ -8,6 +8,10 @@ function getMappingFromBabel(start) {
     const c = findBabelConfig(start);
     if (c && c.config && Array.isArray(c.config.plugins)) {
         const pluginConfig = c.config.plugins.find(p => p[0] === 'module-alias');
+        // The src path inside babelrc are from the root so we have
+        // to change the working directory for the "current file directory"
+        // in order for the mapping in the editor (atom/sublime) to work properly
+        process.chdir(path.dirname(c.file));
         return pluginConfig[1];
     }