Add Makefile and Travis CI build (open-telemetry#200)

* Add Makefile and Travis CI build

* Simplify the script

* Add to contributing guideline

* Include Go modules and tools.go

* Remove new line at eof

Author: songy23

.travis.yml

@@ -0,0 +1,17 @@
+language: go
+cache:
+  directories:
+    - /home/travis/gopath/pkg/mod
+
+go:
+  - 1.12.x
+
+env:
+  global:
+    GO111MODULE=on
+
+install:
+  - make install-tools
+
+script:
+  - make travis-ci

CONTRIBUTING.md

@@ -19,3 +19,19 @@ We highly encourage to use line breaks in markdown files at `80` characters
 wide. There are tools that can do it for you effectively. Please submit proposal
 to include your editor settings required to enable this behavior so the out of
 the box settings for this repository will be consistent.
+
+In addition, please make sure to clean up typos before you submit the change.
+
+To check for typos, use
+
+```bash
+# Golang is needed for the misspell tool.
+make install-tools
+make misspell
+```
+
+To quickly fix typos, use
+
+```bash
+make misspell-correction
+```

Makefile

@@ -0,0 +1,21 @@
+# All documents to be used in spell check.
+ALL_DOC := $(shell find . -name '*.md' -type f | sort)
+
+MISSPELL=misspell -error
+MISSPELL_CORRECTION=misspell -w
+
+.PHONY: travis-ci
+travis-ci: misspell
+
+.PHONY: misspell
+misspell:
+	$(MISSPELL) $(ALL_DOC)
+
+.PHONY: misspell-correction
+misspell-correction:
+	$(MISSPELL_CORRECTION) $(ALL_DOC)
+
+.PHONY: install-tools
+install-tools:
+	GO111MODULE=on go install \
+	  github.com/client9/misspell/cmd/misspell

go.mod

@@ -0,0 +1,5 @@
+module github.com/open-telemetry/opentelemetry-specification
+
+go 1.12
+
+require github.com/client9/misspell v0.3.4

go.sum

@@ -0,0 +1,2 @@
+github.com/client9/misspell v0.3.4 h1:ta993UF76GwbvJcIo3Y68y/M3WxlpEHPWIGDkJYwzJI=
+github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=

internal/tools.go

@@ -0,0 +1,27 @@
+// Copyright 2019, OpenTelemetry 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.
+//
+
+// +build tools
+
+package internal
+
+// This file follows the recommendation at
+// https://github.com/golang/go/wiki/Modules#how-can-i-track-tool-dependencies-for-a-module
+// on how to pin tooling dependencies to a go.mod file.
+// This ensures that all systems use the same version of tools in addition to regular dependencies.
+
+import (
+	_ "github.com/client9/misspell/cmd/misspell"
+)