[test] remove test_libs

Reasons:
1) all deps we're using should be passing tests (including external)
2) deps can require complicated setup for testing
3) the person responsible for releasing Tendermint should be cautious
when updating a dep

scripts/dep_utils/checkout.sh

@@ -1,35 +0,0 @@
-#! /bin/bash
-
-set -ex
-
-set +u
-if [[ "$DEP" == "" ]]; then
-	DEP=$GOPATH/src/github.com/tendermint/tendermint/Gopkg.lock
-fi
-set -u
-
-
-set -u
-
-function getVendoredVersion() {
-	grep -A100 "$LIB" "$DEP" | grep revision | head -n1 | grep -o '"[^"]\+"' | cut -d '"' -f 2
-}
-
-
-# fetch and checkout vendored dep
-
-lib=$1
-
-echo "----------------------------------"
-echo "Getting $lib ..."
-go get -t "github.com/tendermint/$lib/..."
-
-VENDORED=$(getVendoredVersion "$lib")
-cd "$GOPATH/src/github.com/tendermint/$lib" || exit
-MASTER=$(git rev-parse origin/master)
-
-if [[ "$VENDORED" != "$MASTER" ]]; then
-	echo "... VENDORED != MASTER ($VENDORED != $MASTER)"
-	echo "... Checking out commit $VENDORED"
-	git checkout "$VENDORED" &> /dev/null
-fi