Phpunit: Deprecate assertInternalType() and assertNotInternalType()

What to use instead?

@narekps https://github.com/sebastianbergmann/phpunit/issues/3369#issue-373445499 links to https://github.com/sebastianbergmann/phpunit/issues/3368.

For those coming from the deprecation in the code, here is a quick summary of the methods to use instead (to save you a click):

• assertIsArray()
• assertIsBool()
• assertIsFloat()
• assertIsInt()
• assertIsNumeric()
• assertIsObject()
• assertIsResource()
• assertIsString()
• assertIsScalar()
• assertIsCallable()
• assertIsIterable()
• assertIsNotArray()
• assertIsNotBool()
• assertIsNotFloat()
• assertIsNotInt()
• assertIsNotNumeric()
• assertIsNotObject()
• assertIsNotResource()
• assertIsNotString()
• assertIsNotScalar()
• assertIsNotCallable()
• assertIsNotIterable()