config changes

• Instead of having separate variables, I added a struct which holds configuration parameters
• Deleted PEMReader.go file
• Added CheckConfigValues and CalculateConfigValues functions
• Defined required, optional and calculated config values
• Changed Makefile so that on local environments, the git branch will be used as version
• Changed run.sh so that on local environments, config.yaml will be used for configuration file

Gopkg.toml

 [[constraint]]
-  branch = "master"
+  branch = "392-fixing-configuration-issues-with-vault-and-default-values"
   name = "code.vereign.com/code/viam-apis"
 
 [[override]]
@@ -10,6 +10,10 @@
   branch = "master"
   name = "golang.org/x/net"
 
+[[constraint]]
+  name = "github.com/grpc-ecosystem/grpc-gateway"
+  version = "1.4.1"
+
 [[constraint]]
   name = "google.golang.org/grpc"
   version = "1.13.0"