Test both dbs (#205)

* move scripts, allow testing both dbs with one cmd

* tidy + vendor

* update test.sh to ignore cache

* put test commands directly in drone.yml

* change CONTRIBUTING slightly

* go ham on the readme

scripts/build.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+set -eu
+
+COMMIT=$(git rev-list -1 HEAD)
+VERSION=$(cat ./version)
+
+CGO_ENABLED=0 go build -trimpath \
+                       -tags 'netgo osusergo static_build' \
+                       -ldflags="-s -w -extldflags '-static' -X 'main.Commit=${COMMIT}' -X 'main.Version=${VERSION}'" \
+                       ./cmd/gotosocial