clean: trim db api (setnx handles potential collisions)

lib/Urupam/DB.pm

@@ -20,48 +20,6 @@ sub get {
     return $promise;
 }
 
-sub set {
-    my ( $self, $key, $value ) = @_;
-    my $promise = Mojo::Promise->new;
-    $self->redis->set(
-        $key => $value,
-        sub {
-            my ( $redis, $err, $result ) = @_;
-            $err ? $promise->reject($err) : $promise->resolve($result);
-        }
-    );
-    return $promise;
-}
-
-sub incr {
-    my ( $self, $key ) = @_;
-    my $promise = Mojo::Promise->new;
-    $self->redis->incr(
-        $key => sub {
-            my ( $redis, $err, $value ) = @_;
-            $err ? $promise->reject($err) : $promise->resolve($value);
-        }
-    );
-    return $promise;
-}
-
-sub exists {
-    my ( $self, $key ) = @_;
-    my $promise = Mojo::Promise->new;
-    $self->redis->exists(
-        $key => sub {
-            my ( $redis, $err, $exists ) = @_;
-            if ($err) {
-                $promise->reject($err);
-            }
-            else {
-                $promise->resolve( $exists ? 1 : 0 );
-            }
-        }
-    );
-    return $promise;
-}
-
 sub setnx {
     my ( $self, $key, $value ) = @_;
     my $promise = Mojo::Promise->new;