all: upgrade golangci-lint and formatters (#240)

script/fmt

@@ -8,8 +8,11 @@ files=$(find . -name '*.go' -not -path '*/stadtx/*')
 
 # Remove blank lines in import blocks. This will force formatting to group
 # imports correctly.
-sed -i.fmtbackup '/^import (/,/)/ { /^$$/ d; }' ${files}
+sed -i.fmtbackup '/^import (/,/)/ { /^[ \t]*$/ d; }' ${files}
 find . -name '*.fmtbackup' -delete
 
-# gofumports is goimports with stricter formatting.
-gofumports -w -local ${repo} ${files}
+# goimports for import grouping.
+goimports -w -local "${repo}" ${files}
+
+# gofumpt for stricter gofmt-compatible format.
+gofumpt -w ${files}