Implement Logger (#228)

* Added new base logger

* updated example and test configs

* updated exchange helpers restful router & server

* logPath is now passed to the logger to remove dependency on common package

* updated everything besides exchanges to use new logger

* alphapoint to bitmex done

* updated bitmex bitstamp bittrex btcc and also performance changes to logger

* btcmarkets coinbase coinut exmo gateio wrappers updated

* gateio and gemini logger updated

* hitbtc huobi itbit & kraken updated

* All exchanges updatd

* return correct error for disabled websocket

* don't disconnect client on invalid json

* updated router internal logging

* log.Fatal to t.Error for tests

* Changed from fatal to error failure to set maxprocs

* output ANSI codes for everything but windows for now due to lack of windows support

* added error handling to logger and unit tests

* clear wording on print -> log.print

* added benchmark test

* cleaned up import sections

* Updated logger based on PR requests (added default config options on failure/setting errors)

* ah this should fix travici enc config issue

* Load entire config and clear out logging to hopefully fix travisci issue

* wording & test error handling

* fixed formatting issues based on feedback

* fixed formatting issues based on feedback

* changed CheckDir to use mkdirall instead of mkdir and other changes based on feedback

logger/logger_types.go

@@ -0,0 +1,34 @@
+package logger
+
+import (
+	"io"
+	"log"
+	"os"
+)
+
+// Logging struct that holds all user configurable options for the logger
+type Logging struct {
+	Enabled      *bool  `json:"enabled,omitempty"`
+	File         string `json:"file"`
+	ColourOutput bool   `json:"colour"`
+	Level        string `json:"level"`
+	Rotate       bool   `json:"rotate"`
+}
+
+var (
+	debugLogger *log.Logger
+	infoLogger  *log.Logger
+	warnLogger  *log.Logger
+	errorLogger *log.Logger
+	fatalLogger *log.Logger
+
+	logFileHandle *os.File
+
+	logOutput io.Writer
+
+	// LogPath location to store logs in
+	LogPath string
+
+	// Logger create a pointer to Logging struct for holding data
+	Logger = &Logging{}
+)