add RegExr.com tip

Should increase both number of submissions & improve the tests themselves.

README.md

@@ -61,6 +61,7 @@ Big thanks to the contributors:
 * [@patmoore](https://github.com/patmoore)
 * [@vaz](https://github.com/vaz)
 * ... might be you! Let's [fork](https://github.com/nghuuphuoc/bootstrapvalidator/fork) and pull a request!
+  * If you submit new RegEx, please build it using [RegExr.com](http://regexr.com/), add several tests that pass and fail there, and include the "share" link in your JS as a `// ` comment.  Example: `// http://regexr.com/38mqi`
 
 ## License
 
@@ -85,4 +86,4 @@ FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-```
+```