Use tags for expcode tests

tests/test_SCDclass.m

@@ -6,7 +6,7 @@ classdef test_SCDclass < matlab.unittest.TestCase
     shot = 65668;
   end
   
-  methods(Test)
+  methods(Test,TestTags={'expcodes'})
     function test_load(testCase)
       SCD.load(testCase.expcode);
     end

tests/test_expcodes.m

@@ -35,7 +35,7 @@ classdef test_expcodes < matlab.unittest.TestCase
     
   end
   
-  methods(Test)
+  methods(Test,TestTags={'expcodes'})
     
     function test_expcode_printinfo(testCase)
       testCase.expcode_obj.printinfo