Adds go module support that came into effect in go version 1.11 (#201)

Adds go module support that came into effect in go version 1.11

testdata/test.sh

@@ -1,19 +0,0 @@
-#!/usr/bin/env bash
-
-set -e
-
-if [ -n "$TRAVIS_BUILD_DIR" ]; then
-    cd $TRAVIS_BUILD_DIR 
-else
-	cd $GOPATH/src/github.com/thrasher-/gocryptotrader
-fi
-
-echo "" > testdata/coverage.txt
-
-for d in $(go list ./... | grep -v vendor); do
-    go test -race -coverprofile=profile.out -covermode=atomic -cover $d
-    if [ -f profile.out ]; then
-        cat profile.out >> testdata/coverage.txt
-        rm profile.out
-    fi
-done