Tls support (#28)

* Adding support for amqp tls connections

* Correcting spacing in the config.go file

* Checking what travis ci gives as a docker version

* Working around a docker-compose bug that prevents  empty defaults

* removed docker-compose version check

This was being used for debugging a build failure and is no
longer needed

* Making a rabbit mq connector that should be more testable in theoryr

* Refactors and initial tests around CreateConnector

- Added ginkgo and gomega for testing
- Test that a connector of the correct type is created
- Moved the instantiation of the connector into mapping.go
- Added a test to mapping.go to assert that the created connector is non nil
- Renamed config on TlsRabbitConnector to config to reduce confusion around
  the config package

* Adding some happy case tests

* Removed some debug calls that were added by accident

* Adding more test coverage

* Adding test coverage around the tls connector

* Switch to using HasPrefix and add additional test coverage around the basic connector

Dockerfile

@@ -15,6 +15,7 @@ RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o rabbit-amazon-for
 FROM alpine:3.8
 
 RUN mkdir -p /config
+RUN mkdir -p /certs
 RUN apk --update upgrade && \
     apk add curl ca-certificates && \
     update-ca-certificates && \

Gopkg.toml

@@ -37,6 +37,10 @@
   branch = "master"
   name = "github.com/streadway/amqp"
 
+[[override]]
+  name = "gopkg.in/fsnotify.v1"
+  source = "https://github.com/fsnotify/fsnotify/tree/v1.4.7"
+
 [prune]
   go-tests = true
   unused-packages = true

README.md

@@ -55,6 +55,20 @@ export AWS_ACCESS_KEY_ID=access_key
 export AWS_SECRET_ACCESS_KEY=secret_key
 ```
 
+#### Using TLS with rabbit
+
+Specify amqps for the rabbit connection ub the mapping file:
+```
+ "connection" : "amqps://guest:guest@localhost:5671/",
+```
+
+Additional environment variables for working with TLS and rabbit:
+```
+export CA_CERT=/certs/ca_certificate.pem
+export CERT_FILE=/certs/client_certificate.pem
+export KEY_FILE=/certs/client_key.pem
+```
+
 ### Amazon configuration
 
 When making subscription to SNS -> SQS/HTTP/HTTPS set `Raw message delivery` to ensure that json messages are not escaped.

config/config.go

@@ -3,6 +3,9 @@ package config
 const (
 	// MappingFile mapping file environment variable
 	MappingFile = "MAPPING_FILE"
+	CaCertFile  = "CA_CERT_FILE"
+	CertFile    = "CERT_FILE"
+	KeyFile     = "KEY_FILE"
 )
 
 // RabbitEntry RabbitMQ mapping entry