[oni-scheme] Check that the output ends with the expected text

All of the other tests already check that the output ends with the expected
output and isn’t exactly equal to it. This is because I don’t have enough
control over (or don’t know enough about) the output Emacs and other packages
generate. In order to prevent false-positives from happening as is happening
with ‘scheme-mode’, I don’t check what’s before the output I expect.

The false-positive that’s happening with ‘scheme-mode’ is an issue that it seems
like ‘geiser’ has started complaining that it can’t find ‘guile’, which is
expected.

test/integration/oni-scheme.bats

@@ -7,7 +7,7 @@
 
     echo "$output"
 
-    [ "$output" = "t" ]
+    [[ "$output" == *"t" ]]
 }
 
 @test "Opening a file with the SCSH interpreter loads scheme-mode" {
@@ -23,5 +23,5 @@
 
     echo "$output"
 
-    [ "$output" = "scheme-mode" ]
+    [[ "$output" == *"scheme-mode" ]]
 }