Fix spacing between Euler subtests

Author: paultcochrane

t/categories/euler.t

@@ -453,6 +453,7 @@ subtest {
 
     check-example-solutions($problem, $expected-output, @authors)
 }, "prob063";
+
 subtest {
     plan 1;
 
@@ -485,6 +486,7 @@ subtest {
 
     check-example-solutions($problem, $expected-output, @authors)
 }, "prob067";
+
 subtest {
     plan  1;
     my $problem = "prob080";
@@ -493,6 +495,7 @@ subtest {
 
     check-example-solutions($problem, $expected-output, @authors)
 }, "prob080";
+
 subtest {
     plan 1;
 
@@ -502,6 +505,7 @@ subtest {
 
     check-example-solutions($problem, $expected-output, @authors)
 }, "prob081";
+
 subtest {
     plan 1;
 
@@ -512,7 +516,6 @@ subtest {
     check-example-solutions($problem, $expected-output, @authors)
 }, "prob089";
 
-
 skip("prob092-moritz.pl takes too long to run");
 unless $skip {
     subtest {
@@ -553,7 +556,6 @@ subtest {
     check-example-solutions($problem, $expected-output, @authors)
 }, "prob099";
 
-
 subtest {
     plan 1;