Update README and CHANGELOG files (#1253)

Author: Sergey Vilgelm

CHANGELOG.md

@@ -1,6 +1,25 @@
 Follow the news and releases on our [twitter](https://twitter.com/golangci) and our [blog](https://medium.com/golangci).
 There is the most valuable changes log:
 
+### July 2020
+
+1. `gofumpt` linter:
+    * update linter
+    * add `extra-rules` option
+    * support auto-fixing
+2. upgrade `exhaustive` linter
+3. upgrade `exportloopref` linter
+4. improve 'no such linter' error message
+5. sorting result.Issues implementation
+6. enhancements in CI:
+    * Run `nancy` validation for all dependencies
+    * Move dependabot config to `.github` folder
+7. other
+    * bump `lodash` from 4.17.15 to 4.17.19 in /tools
+    * bump `golangci/golangci-lint-action` from v1.2.2 to v2
+    * bump `github.com/valyala/quicktemplate` from 1.5.0 to 1.5.1
+
+
 ### June 2020
 1. Add new linters: `gofumpt`