Fix tests for R3.0.3

[Thomas J. Leeper]

http://cran.r-project.org/web/checks/check_results_UNF.html

Check Details

Version: 2.0 
Check: tests 
Result: ERROR 
    Running the tests in 'tests/test-all.R' failed.
    Last 13 lines of output:

     3. Failure(@test-unf6-datetimes.R#7): Examples from v6 specification -----------
     unf6("2014-08-22T16:51:05Z") not equal to unf6(strptime("2014-08-22T16:51:05Z", "%FT%H:%M:%OSZ", tz = "UTC"), timezone = "UTC")
     Component 1: 1 string mismatch
     Component 2: 32 element mismatches
     Component 3: 1 string mismatch
     Component 4: 1 string mismatch

     4. Failure(@test-unf6-datetimes.R#16): UNFs differ by timezone -----------------
     identical(unf6(strptime("2014-08-22T16:51:05Z", "%FT%H:%M:%OSZ", tz = "UTC"), timezone = "UTC"), unf6(strptime("2014-08-22T16:51:05Z", "%FT%H:%M:%OSZ", tz = "US/Eastern"), timezone = "UTC")) isn't false

     Error: Test failures
     Execution halted 
Flavor: r-oldrel-windows-ix86+x86_64

[Thomas J. Leeper]

The problem is here: https://github.com/leeper/UNF/blob/master/R/unf6.R#L63-L65

I've opened a StackOverflow question to try to track down a solution.