Handle case if directory does not exist in FilePicker

Fixes #4

gradle.properties

@@ -17,8 +17,8 @@
 
 # Project-wide Gradle settings.
 
-VERSION_NAME=1.1.2-SNAPSHOT
-VERSION_CODE=4
+VERSION_NAME=1.1.3-SNAPSHOT
+VERSION_CODE=5
 GROUP=com.nononsenseapps
 
 POM_DESCRIPTION=An extendable Android file/directory-picker you can include in your app

library/src/main/java/com/nononsenseapps/filepicker/FilePickerFragment.java

@@ -155,6 +155,11 @@ public class FilePickerFragment extends AbstractFilePickerFragment<File> {
             protected void onStartLoading() {
                 super.onStartLoading();
 
+                // handle if directory does not exist. Fall back to root.
+                if (currentPath == null || !currentPath.isDirectory()) {
+                    currentPath = getRoot();
+                }
+
                 // Start watching for changes
                 fileObserver = new FileObserver(currentPath.getPath(),
                         FileObserver.CREATE |