Web Support

[aurangzaibsiddiqui]

Currently Firebase Image does not work with the web.

I received the following error when I tried it on web:

════════ Exception caught by image resource service ════════════════════════════
MissingPluginException(No implementation found for method getDatabasesPath on channel com.tekartik.sqflite)
════════════════════════════════════════════════════════════════════════════════

It is working perfectly on iOS and Android.

[andressilvac]

I believe this is the same issue as #48. We should probably leave just one, what do you think?

#36 might be a solution to this.