Merge pull request #2977 from flip1995/tool_lints

Implement tool_lints

clippy_lints/src/strings.rs

@@ -1,6 +1,6 @@
 use rustc::hir::*;
 use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_lint, lint_array};
+use rustc::{declare_tool_lint, lint_array};
 use syntax::source_map::Spanned;
 use crate::utils::SpanlessEq;
 use crate::utils::{get_parent_expr, is_allowed, match_type, paths, span_lint, span_lint_and_sugg, walk_ptrs_ty};