Replace stella-maris/clock with psr/clock

src/Clock/FrozenClock.php

@@ -7,7 +7,7 @@ namespace Beste\Clock;
 use Beste\Clock;
 use DateTimeImmutable;
 use DateTimeZone;
-use StellaMaris\Clock\ClockInterface;
+use Psr\Clock\ClockInterface;
 
 final class FrozenClock implements Clock
 {

src/Clock/MinuteClock.php

@@ -6,7 +6,7 @@ namespace Beste\Clock;
 
 use Beste\Clock;
 use DateTimeImmutable;
-use StellaMaris\Clock\ClockInterface;
+use Psr\Clock\ClockInterface;
 
 final class MinuteClock implements Clock
 {

src/Clock/WrappingClock.php

@@ -6,7 +6,7 @@ namespace Beste\Clock;
 
 use Beste\Clock;
 use DateTimeImmutable;
-use StellaMaris\Clock\ClockInterface;
+use Psr\Clock\ClockInterface;
 
 final class WrappingClock implements Clock
 {