Build improvments (#179)

* Add a semantic version to the usage text

* Add a comment to the version function

* Inject the version, git tag and build date as build variables

* Update README

* Fix lint warnings

* Update README

* Manage dependencies with dep tool instead of godep

* Add a Makefile for common build tasks

* Update the build file to use the make tool

* Update Dockerfile

* Add docker entry point in to make the passing of arguments easy

* Update README

* Add missing tools to the build

* Drop 1.7 support and add 1.10

* Fix Go 1.10 according with the travis guidelines

https://docs.travis-ci.com/user/languages/go/

* Update the tls-observatory package

* Fix lint warnings

* Change the output of the tests to be more verbose

* Check if the are build errors before executing the rule test

rules/rules_test.go

@@ -32,9 +32,10 @@ var _ = Describe("gas rules", func() {
 				pkg := testutils.NewTestPackage()
 				defer pkg.Close()
 				pkg.AddFile(fmt.Sprintf("sample_%d.go", n), sample.Code)
-				pkg.Build()
-				e := analyzer.Process(pkg.Path)
-				Expect(e).ShouldNot(HaveOccurred())
+				err := pkg.Build()
+				Expect(err).ShouldNot(HaveOccurred())
+				err = analyzer.Process(pkg.Path)
+				Expect(err).ShouldNot(HaveOccurred())
 				issues, _ := analyzer.Report()
 				if len(issues) != sample.Errors {
 					fmt.Println(sample.Code)