feat: absolute imports (#63)

* feat: go-like import style

jb now creates a directory structure inside of vendor/ that is similar to how go
does (github.com/grafana/jsonnet-libs). This is reflected in the final import
paths, which means they will be go-like

* refactor(spec/deps): named regexs

* feat: make goImportStyle configurable

Defaults to off, can be enabled in `jsonnetfile.json`

* fix: integration test

* doc: license headers

* fix(deps): remove GO_IMPORT_STYLE

not an option anymore, will always do so and symlink

* feat: symlink to legacy location

* feat: allow to disable legacy links

* fix(test): legacyImports in integration tests

* fix(spec): test

* fix: respect legacyName aliases

It was possible to alias packages by changing `name` previously.

While names are now absolute (and computed), legacy links should still respect
old aliases to avoid breaking code.

* fix(test): integration

* fix(init): keep legacyImports enabled for now

* feat: rewrite imports

adds a command to automatically rewrite imports from legacy to absolute style

* fix(tool): rewrite confused by prefixing packages

When a package was a prefix of another one, it broke.
Fixed that by using a proper regular expression. Added a test to make sure it
works as expected

* Update cmd/jb/init.go

* fix: exclude local packages from legacy linking

They actually still use the old style, which is fine. LegacyLinking
messed them up, but from now on it just ignores symlinks that match a localPackage.

spec/deps/git_test.go

@@ -0,0 +1,68 @@
+// Copyright 2018 jsonnet-bundler authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package deps
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestParseGit(t *testing.T) {
+	tests := []struct {
+		name       string
+		uri        string
+		want       *Dependency
+		wantRemote string
+	}{
+		{
+			name: "GitHub",
+			uri:  "github.com/ksonnet/ksonnet-lib/ksonnet.beta.3",
+			want: &Dependency{
+				Version: "master",
+				Source: Source{GitSource: &Git{
+					Scheme: GitSchemeHTTPS,
+					Host:   "github.com",
+					User:   "ksonnet",
+					Repo:   "ksonnet-lib",
+					Subdir: "/ksonnet.beta.3",
+				}},
+			},
+			wantRemote: "https://github.com/ksonnet/ksonnet-lib",
+		},
+		{
+			name: "SSH",
+			uri:  "git+ssh://git@my.host:user/repo.git/foobar@v1",
+			want: &Dependency{
+				Version: "v1",
+				Source: Source{GitSource: &Git{
+					Scheme: GitSchemeSSH,
+					Host:   "my.host",
+					User:   "user",
+					Repo:   "repo",
+					Subdir: "/foobar",
+				}},
+			},
+			wantRemote: "ssh://git@my.host:user/repo.git",
+		},
+	}
+
+	for _, c := range tests {
+		t.Run(c.name, func(t *testing.T) {
+			got := Parse("", c.uri)
+			assert.Equal(t, c.want, got)
+			assert.Equal(t, c.wantRemote, got.Source.GitSource.Remote())
+		})
+	}
+}