* experimenting with psalm
* loading in symfony polyfill, partially resolvesegulias/EmailValidator#177, but SpoofChecker does not seem to be polyfilled in symfony/polyfill-intl-*
* removing unused imports, fixesegulias/EmailValidator#168 and egulias/EmailValidator#169
* not actually used for object storage
* Egulias\Tests\EmailValidator\Validation\SpoofCheckValidationTest::testEmailWithSpoofsIsInvalid fails if extension is not installed
* satisfying psalm
* amending indentation
* disabling psalm on 5.6
* attempting to resolve psalm issue on 7.0 & 7.1
* dropping psalm from 7.0 matrix
* ext-intl removed as per egulias/EmailValidator#231
* updating baseline with psalm 3.8.3
* suppressing issue with Spoofchecker not being present, pending resolution of egulias/EmailValidator#231
* enable psalm on travis config for php 7.3