Update Readme.md

Practical Tips/Readme.md

@@ -3,7 +3,7 @@
 * [Using github](https://github.com/dssg/hitchhikers-guide/tree/master/curriculum/git-and-github)
 * [Working with data using the unix command line](https://github.com/dssg/hitchhikers-guide/tree/master/curriculum/command-line-tools)
 * [Loading data in to databases](https://github.com/dssg/hitchhikers-guide/tree/master/curriculum/csv-to-db)
-* [Data Exploration Tips](Data-Exploration.md)
+* [Data Exploration Tips](Data%20Exploration.md)
 * Feature Generation Tips
 * Modeling Tips: What models to use, which hyperparemeters to try,...
 * Evaluation Tips