Fix specs against Crystal nightly

spec/ameba/rule/lint/shadowing_outer_local_var_spec.cr

@@ -44,7 +44,7 @@ module Ameba::Rule::Lint
           foo = 1
 
           -> (foo : Int32) {}
-            # ^ error: Shadowing outer local variable `foo`
+            # ^^^^^^^^^^^ error: Shadowing outer local variable `foo`
         end
         CRYSTAL
     end
@@ -69,7 +69,7 @@ module Ameba::Rule::Lint
         3.times do |foo|
                   # ^ error: Shadowing outer local variable `foo`
           -> (foo : Int32) { foo + 1 }
-            # ^ error: Shadowing outer local variable `foo`
+            # ^^^^^^^^^^^ error: Shadowing outer local variable `foo`
         end
         CRYSTAL
     end

spec/ameba/rule/lint/spec_focus_spec.cr

@@ -115,12 +115,12 @@ module Ameba::Rule::Lint
 
       first.rule.should_not be_nil
       first.location.to_s.should eq "source_spec.cr:1:11"
-      first.end_location.to_s.should eq ""
+      first.end_location.to_s.should eq "source_spec.cr:1:21"
       first.message.should eq "Focused spec item detected"
 
       second.rule.should_not be_nil
       second.location.to_s.should eq "source_spec.cr:2:13"
-      second.end_location.to_s.should eq ""
+      second.end_location.to_s.should eq "source_spec.cr:2:23"
       second.message.should eq "Focused spec item detected"
     end
   end

spec/ameba/rule/lint/unused_argument_spec.cr

@@ -52,7 +52,7 @@ module Ameba::Rule::Lint
     it "reports if proc argument is unused" do
       source = expect_issue subject, <<-CRYSTAL
         -> (a : Int32, b : String) do
-                     # ^ error: Unused argument `b`. If it's necessary, use `_b` as an argument name to indicate that it won't be used.
+                     # ^^^^^^^^^^ error: Unused argument `b`. If it's necessary, use `_b` as an argument name to indicate that it won't be used.
           a = a + 1
         end
         CRYSTAL
@@ -306,7 +306,7 @@ module Ameba::Rule::Lint
 
           expect_issue rule, <<-CRYSTAL
             ->(a : Int32) {}
-             # ^ error: Unused argument `a`. If it's necessary, use `_a` as an argument name to indicate that it won't be used.
+             # ^^^^^^^^^ error: Unused argument `a`. If it's necessary, use `_a` as an argument name to indicate that it won't be used.
             CRYSTAL
         end
       end