CI: Travis macOS: Skip tab left-drag tests.

These tests fail on master, so it's not a regression. Changes in neovim#4874
(parent commit) seem to work (and pass most CI), so skipping these tests
is better than blocking the changes.

test/functional/api/server_requests_spec.lua

@@ -141,8 +141,8 @@ describe('server -> client', function()
 
   describe('when the client is a recursive vim instance', function()
     if os.getenv("TRAVIS") and helpers.os_name() == "osx" then
-      -- XXX: Hangs Travis OSX since e9061117a5b8f195c3f26a5cb94e18ddd7752d86.
-      pending("[Hangs on Travis OSX. #5002]", function() end)
+      -- XXX: Hangs Travis macOS since e9061117a5b8f195c3f26a5cb94e18ddd7752d86.
+      pending("[Hangs on Travis macOS. #5002]", function() end)
       return
     end
 

test/functional/core/job_spec.lua

@@ -109,8 +109,8 @@ describe('jobs', function()
   it("will not buffer data if it doesn't end in newlines", function()
     if os.getenv("TRAVIS") and os.getenv("CC") == "gcc-4.9"
       and helpers.os_name() == "osx" then
-      -- XXX: Hangs Travis OSX since e9061117a5b8f195c3f26a5cb94e18ddd7752d86.
-      pending("[Hangs on Travis OSX. #5002]", function() end)
+      -- XXX: Hangs Travis macOS since e9061117a5b8f195c3f26a5cb94e18ddd7752d86.
+      pending("[Hangs on Travis macOS. #5002]", function() end)
       return
     end
 

test/functional/ui/mouse_spec.lua

@@ -153,6 +153,11 @@ describe('Mouse input', function()
     end)
 
     it('in tabline to the left moves tab left', function()
+      if os.getenv("TRAVIS") and helpers.os_name() == "osx" then
+        pending("[Hangs on Travis macOS. #4874]", function() end)
+        return
+      end
+
       execute('%delete')
       insert('this is foo')
       execute('silent file foo | tabnew | file bar')
@@ -251,6 +256,11 @@ describe('Mouse input', function()
     end)
 
     it('out of tabline to the left moves tab left', function()
+      if os.getenv("TRAVIS") and helpers.os_name() == "osx" then
+        pending("[Hangs on Travis macOS. #4874]", function() end)
+        return
+      end
+
       execute('%delete')
       insert('this is foo')
       execute('silent file foo | tabnew | file bar')