Use Go 1.16 and bump dependencies

The build was failing due to using a package, io/fs, that was introduced
in Go 1.16 because go mods was resolving the wrong version of afero.
I've updated our dependencies to resolve the conflict.

Signed-off-by: Carolyn Van Slyck <[email protected]>

Author: carolynvs

azure-pipelines.yml

@@ -15,7 +15,7 @@ pool:
 steps:
 - task: GoTool@0
   inputs:
-    version: '1.13.10'
+    version: '1.16'
   displayName: 'Install Go'
 
 - script: |

go.mod

@@ -1,17 +1,16 @@
 module get.porter.sh/mixin/kubernetes
 
-go 1.15
+go 1.16
 
 replace github.com/hashicorp/go-plugin => github.com/carolynvs/go-plugin v1.0.1-acceptstdin
 
 require (
-	get.porter.sh/porter v0.37.2
+	get.porter.sh/porter v0.38.7
 	github.com/Masterminds/semver v1.5.0
 	github.com/ghodss/yaml v1.0.0
-	github.com/gobuffalo/packr/v2 v2.8.0
 	github.com/pkg/errors v0.9.1
-	github.com/spf13/cobra v1.0.0
-	github.com/stretchr/testify v1.6.1
+	github.com/spf13/cobra v1.1.3
+	github.com/stretchr/testify v1.7.0
 	github.com/xeipuuv/gojsonschema v1.2.0
-	gopkg.in/yaml.v2 v2.2.4
+	gopkg.in/yaml.v2 v2.4.0
 )