vendor: Update testify for latest assert

Re-vendor the testify package to obtain the newest assert test
functions.

Shortlog:

    87b1dfb Remove returns info from assertion docs
    bf45a85 Skip vendored packages from tests
    2c9035a Changed mock assertions text output to be non-unicode friendly
    05aa1d4 Remove outdated info from README
    b91bfb9 Move from Godep to dep for dependency management
    9ede17e Drop old Go versions from tests
    8de2544 Fix HTTP assertions to be consistent with the rest
    b57b6d1 Add FileExists and DirExists assertions
    b3596e9 Fxinng After(time.Duration) to wait properly
    cbf22d8 Support nil arguments to Argument Matchers
    42baa3e Nil check in Implements assertion
    b3dfaa9 fail: add test name for logged output
    6e494f9 put closestCall.Arguments to the expected side of the diff
    51464da Consider empty/nil arrays as matching elements
    6f306a6 Reuse aLen and bLen variables
    76de30e Actually fail tests
    ae87ba6 Ran go generate
    8bd27dd Compress some newlines
    bf57a5d ElementsMatch array/slice assertion ignoring order
    0c49dd9 Replace is with in
    9fb9de1 Make NotSubset actually fail the test on nil subset
    8ccf48a Allow a method call to be optional
    aa8279e travis: add go1.9
    c0f1d44 indent actual value for better comparison with expected value
    249123e Implement delta comparison for map values
    88a414d generalize Empty assertion
    2aa2c17 Fix unprotected call fields access in MethodCalled()
    890a5c3 Issue kata-containers#469 fix
    05e8a0e Fix the actuality of InEpsilon
    2f1cd6b time.Duraions are numbers too
    b1f9894 Fix InDelta expected nan check message
    4b92304 Fix actual float conversion error message under calcRelativeError
    f6abca5 Added assert.PanicsWithValue + tests
    e964b17 add MethodCalled to the mock
    46b3c82 Simple validation of Equal/NotEqual assertion arguments
    cc18973 Fix gogenerate travis check
    e179a18 Travis check go generate has been run
    3458981 Run go vet in travis
    c7668ea Fixes kata-containers#339 - Add `assertion`f assertions like Errorf and Equalf
    c33f336 Fix vet warnings and go generate to update docs
    3104bf5 Use Go 1.7 subtests so suites can properly nest
    bd79c01 Fix race condition on mock package's Called
    edd8e19 Run go generate to syn generated assertions
    78be756 Fixed HTTP assertions messages formatting and removed wrong test message
    3a59a58 add Subset and NotSubset assertions
    dd57c7b Check code is formatted in travis
    f712be9 Revert "add mock.MethodCalled(methodName, args...)"
    34687eb Revert "diffArguments: remove unnecessary range-for (kata-containers#417)"
    2b76a97 Revert "Added goconvey style assertions to the mock package"
    b6296e3 fix(docs): correct Error usage examples
    d2f3716 Add msgAndArgs pass forward to InDelta from InDeltaSlice
    158f9d0 Check that there is a directory before trying to access it.
    18cfa68 Added extra unit test for function with mixed variadic arguments.
    b1f1bcb fix typo
    09f61d7 assert: fix error reporting when error contains escape sequences
    5c861cc diffArguments: remove unnecessary range-for (kata-containers#417)
    bc11a6e Tighten language by increasing overall consistency in wording in texts and argument names: use 'actual' instead of 'received'
    115ab90 Provide argument name `args` in function signature
    faf0710 Added goconvey style assertions to the mock package
    97c0e43 compare bytes with bytes.Equal instead of reflect.DeepEqual
    17a0bd5 add mock.MethodCalled(methodName, args...)
    9afdd65 Check number of provided arguments vs mocked
    287336f travis: rm broken go releases
    32d79c5 travis: check if these platforms are broken
    5c9da49 HTTP code status assertions now fail tests
    332ae0e Add Equal test comparing nil with non-nil
    434d5c1 Fixed minor typo
    3928f57 Add comments for Equal and NotEqual to clarify pointer comparison
    13b9dd4 Fix typos in comments in _codegen/main.go
    6835870 Remove isNumericType check
    cbd71e7 When diffing with spew, use a format that doesn't include pointer addresses (which generate false negatives). This updates go-spew to 04cdfd42973bb9c8589fd6a731800cf222fde1a9.
    ddb91ee Ensure that assert.Fail properly align its output
    5e72f93 Remove timestamp from callback
    976c720 Format generated code
    4b9bfb8 run go/format on generated code
    4ccf54a Clearer messages
    bf7a93e Add timestamp
    fcedfe2 Add callbacks to run before and after each test
    8879a01 Unlock and relock not needed anymore. Addresses kata-containers#167.
    4a6e516 Added test to avoid regresions of kata-containers#167.
    547cd8e Release lock before .WaitUntil, as it may cause a deadlock when testing parallel objects. Address kata-containers#167: Unable to test concurrent objects

Signed-off-by: James O. D. Hunt <[email protected]>

Gopkg.toml

@@ -28,7 +28,7 @@
 
 [[constraint]]
   name = "github.com/stretchr/testify"
-  revision = "69483b4bd14f5845b5a1e55bca19e954e827f1d0"
+  revision = "87b1dfb5b2fa649f52695dd9eae19abe404a4308"
 
 [[constraint]]
   name = "github.com/vishvananda/netlink"