Update the path_provider dependecy

[rauleburro]

The actual path_provider dependency has incompatibilities when i install the localstorage with the last version of shared_preferences

Because shared_preferences >=2.0.0 depends on shared_preferences_windows ^2.0.0 which depends on path_provider_platform_interface ^2.0.0, shared_preferences >=2.0.0 requires path_provider_platform_interface ^2.0.0.
Because localstorage >=3.0.3+6 depends on path_provider ^1.6.14 which depends on path_provider_platform_interface ^1.0.1, localstorage >=3.0.3+6 requires path_provider_platform_interface ^1.0.1.

Thus, shared_preferences >=2.0.0 is incompatible with localstorage >=3.0.3+6.

So, because uberlike depends on both localstorage ^3.0.6+9 and shared_preferences ^2.0.3, version solving failed.

[lesnitsky]

fixed in #70