Initial commit

This commit is the initial commit for a Go library providing an
idiomatic, easy-to-use query builder for ElasticSearch. The library can
build queries and execute them using the structures from the official Go
SDK provided by the ES project (https://github.com/elastic/go-elasticsearch).

The library currently provides the capabilities to create and execute
simple ElasticSearch queries, specifically Match queries (match,
match_bool_prefix, match_phrase and match_phrase_prefix), Match All
queries (match_all, match_none), and all of the Term-level queries (e.g.
range, regexp, etc.).

Unit tests are included for each support query, and the code is linted
using golangci-lint (see enabled linters in .golangci-lint). The unit
tests currently only verify the builder creates valid JSON queries and
does not attempt to actually run queries against a (mock) ES instance.

match_all_test.go

@@ -0,0 +1,13 @@
+package esquery
+
+import (
+	"testing"
+)
+
+func TestMatchAll(t *testing.T) {
+	runTests(t, []queryTest{
+		{"match_all without a boost", MatchAll(), "{\"match_all\":{}}\n"},
+		{"match_all with a boost", MatchAll().Boost(2.3), "{\"match_all\":{\"boost\":2.3}}\n"},
+		{"match_none", MatchNone(), "{\"match_none\":{}}\n"},
+	})
+}