Remove fish completion script

fish ships with a much more capable rbenv completion script since fish 2.0.

Fixes #1212

completions/rbenv.zsh

@@ -1,18 +0,0 @@
-if [[ ! -o interactive ]]; then
-    return
-fi
-
-compctl -K _rbenv rbenv
-
-_rbenv() {
-  local words completions
-  read -cA words
-
-  if [ "${#words}" -eq 2 ]; then
-    completions="$(rbenv commands)"
-  else
-    completions="$(rbenv completions ${words[2,-2]})"
-  fi
-
-  reply=("${(ps:\n:)completions}")
-}

libexec/rbenv-init

@@ -92,14 +92,14 @@ fish )
 * )
   echo 'export PATH="'${RBENV_ROOT}'/shims:${PATH}"'
   echo "export RBENV_SHELL=$shell"
+
+  completion="${root}/completions/rbenv.${shell}"
+  if [ -r "$completion" ]; then
+    echo "source '$completion'"
+  fi
 ;;
 esac
 
-completion="${root}/completions/rbenv.${shell}"
-if [ -r "$completion" ]; then
-  echo "source '$completion'"
-fi
-
 if [ -z "$no_rehash" ]; then
   echo 'command rbenv rehash 2>/dev/null'
 fi

test/init.bats

@@ -43,11 +43,12 @@ OUT
   assert_success "sh"
 }
 
-@test "setup shell completions (fish)" {
+@test "skip shell completions (fish)" {
   root="$(cd $BATS_TEST_DIRNAME/.. && pwd)"
   run rbenv-init - fish
   assert_success
-  assert_line "source '${root}/test/../libexec/../completions/rbenv.fish'"
+  local line="$(grep '^source' <<<"$output")"
+  [ -z "$line" ] || flunk "did not expect line: $line"
 }
 
 @test "fish instructions" {