Switch to go modules, update readme and makefile

Makefile

@@ -1,7 +1,8 @@
+GO111MODULE=on
 SHELL=/bin/bash
-BINARY_NAME:="kubectl-ksd"
-GOPATH:="${HOME}/go"
+BINARY_NAME:=kubectl-ksd
+GOPATH:=${HOME}/go
 
 .PHONY: install
 install: ## Install the binary 
-	@go build -o ${GOPATH}/bin/${BINARY_NAME}
+	@go build -o "${GOPATH}/bin/${BINARY_NAME}"

README.md

@@ -44,15 +44,17 @@ type: Opaque
 ### Installation
 
 These instructions assume you have go installed and a `$GOPATH` set.
-The binary needs to be installed somewhere in your `$PATH`.
-The binary also needs to be named either `kubectl-ksd` or `kubectl-kubernetes-secret-decode`
+If you have not set `$GOPATH` it will be assumed to be `$HOME/go`
 
-For easy install running the following:
+For easy install, running the following:
 ```
 make install
 ```
 
-Another option is to download the binary and add it to your path
+Another option is to download the binary and add it to your path.
+The binary needs to be installed somewhere in your system `$PATH`.
+The binary also needs to be named either `kubectl-ksd` or `kubectl-kubernetes-secret-decode`
+
 ```
 curl -LO https://github.com/ashleyschuett/kubernetes-secret-decode/releases/download/v3.0.0/kubectl-ksd && chmod +x ksd && sudo mv ksd /usr/local/bin
 ```

go.mod

@@ -0,0 +1,5 @@
+module github.com/ashleyschuett/kubernetes-secret-decode
+
+go 1.12
+
+require gopkg.in/yaml.v2 v2.2.1

go.sum

@@ -0,0 +1,4 @@
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
+gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=