Update default strikethrough tag in tests

Author: cameronvoell

app/src/androidTest/kotlin/org/wordpress/aztec/demo/tests/FormattingHistoryTests.kt

@@ -232,7 +232,7 @@ class FormattingHistoryTests : BaseHistoryTest() {
     fun testMakeStrikethroughUndoRedo() {
         val snippet1 = "There's no crying in"
         val snippet2 = " baseball!"
-        val html = "$snippet1<del>$snippet2</del>"
+        val html = "$snippet1<s>$snippet2</s>"
         val editorPage = EditorPage()
 
         // Insert first snippet

app/src/androidTest/kotlin/org/wordpress/aztec/demo/tests/SimpleTextFormattingTests.kt

@@ -46,7 +46,7 @@ class SimpleTextFormattingTests : BaseTest() {
     fun testSimpleStrikethroughFormatting() {
         val text1 = "some"
         val text2 = "text"
-        val html = "$text1<del>$text2</del>"
+        val html = "$text1<s>$text2</s>"
 
         EditorPage()
                 .insertText(text1)
@@ -351,7 +351,7 @@ class SimpleTextFormattingTests : BaseTest() {
     fun testInlineStyleAndSpace() {
         val text1 = "some"
         val text2 = "text "
-        val html = "$text1<del>$text2</del>"
+        val html = "$text1<s>$text2</s>"
 
         EditorPage()
                 .insertText(text1)

aztec/src/test/kotlin/org/wordpress/aztec/LinkTest.kt

@@ -47,11 +47,11 @@ class LinkTest {
     @Test
     @Throws(Exception::class)
     fun insertLinkIntoStyledText() {
-        editText.fromHtml("<del><b>left</b><i>right</i></del>")
+        editText.fromHtml("<s><b>left</b><i>right</i></s>")
         editText.setSelection(4)
         editText.link("http://wordpress.com", "WordPress")
         // Still valid, but order of b and del is switched here for some reason.
-        Assert.assertEquals("<b><del>left</del></b><b><del><a href=\"http://wordpress.com\">WordPress</a></del></b><del><i>right</i></del>", editText.toHtml())
+        Assert.assertEquals("<b><s>left</s></b><b><s><a href=\"http://wordpress.com\">WordPress</a></s></b><s><i>right</i></s>", editText.toHtml())
     }
 
     @Test