build(deps): bump golang from 1.15.6 to 1.15.7 (#855)

Bumps golang from 1.15.6 to 1.15.7.

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Dockerfile

@@ -1,5 +1,5 @@
 # STEP 1: Build sqlc
-FROM golang:1.15.6 AS builder
+FROM golang:1.15.7 AS builder
 
 COPY . /workspace
 WORKDIR /workspace