Change TachyonFS to have URI methods
Refactor client module to use TachyonURI instead of Strings.
Merge master & resolve conflicts
Move deprecated methods from interface to implementation (TachyonFS)
Validate Tachyon URIs in TachyonFS.
Merge pull request #400 from calvinjia/tachyon-14_2

[Tachyon-14] TachyonURI (Client)
Revert "[Tachyon-14] TachyonURI (Client)"
Merge pull request #407 from amplab/revert-400-tachyon-14_2

Revert "[Tachyon-14] TachyonURI (Client)"