Fix golint warnings

- The ones left are "uncommented exported func/var/methods etc"

directives.go

@@ -1,5 +1,7 @@
 package graphql
 
+// Directive structs are used by the GraphQL runtime as a way of modifying execution
+// behavior. Type system creators will usually not create these directly.
 type Directive struct {
 	Name        string      `json:"name"`
 	Description string      `json:"description"`
@@ -9,10 +11,6 @@ type Directive struct {
 	OnField     bool        `json:"onField"`
 }
 
-/**
- * Directives are used by the GraphQL runtime as a way of modifying execution
- * behavior. Type system creators will usually not create these directly.
- */
 func NewDirective(config *Directive) *Directive {
 	if config == nil {
 		config = &Directive{}
@@ -27,10 +25,8 @@ func NewDirective(config *Directive) *Directive {
 	}
 }
 
-/**
- * Used to conditionally include fields or fragments
- */
-var IncludeDirective *Directive = NewDirective(&Directive{
+// IncludeDirective is used to conditionally include fields or fragments
+var IncludeDirective = NewDirective(&Directive{
 	Name: "include",
 	Description: "Directs the executor to include this field or fragment only when " +
 		"the `if` argument is true.",
@@ -46,10 +42,8 @@ var IncludeDirective *Directive = NewDirective(&Directive{
 	OnField:     true,
 })
 
-/**
- * Used to conditionally skip (exclude) fields or fragments
- */
-var SkipDirective *Directive = NewDirective(&Directive{
+// SkipDirective Used to conditionally skip (exclude) fields or fragments
+var SkipDirective = NewDirective(&Directive{
 	Name: "skip",
 	Description: "Directs the executor to skip this field or fragment when the `if` " +
 		"argument is true.",

executor.go

@@ -109,9 +109,8 @@ func buildExecutionContext(p BuildExecutionCtxParams) (*ExecutionContext, error)
 	if operation == nil {
 		if p.OperationName == "" {
 			return nil, fmt.Errorf(`Unknown operation named "%v".`, p.OperationName)
-		} else {
-			return nil, fmt.Errorf(`Must provide an operation`)
 		}
+		return nil, fmt.Errorf(`Must provide an operation`)
 	}
 
 	variableValues, err := getVariableValues(p.Schema, operation.GetVariableDefinitions(), p.Args)
@@ -156,9 +155,9 @@ func executeOperation(p ExecuteOperationParams) *Result {
 
 	if p.Operation.GetOperation() == "mutation" {
 		return executeFieldsSerially(executeFieldsParams)
-	} else {
-		return executeFields(executeFieldsParams)
 	}
+	return executeFields(executeFieldsParams)
+
 }
 
 // Extracts the root type of the operation from the schema.
@@ -470,12 +469,10 @@ type resolveFieldResultState struct {
 	hasNoFieldDefs bool
 }
 
-/**
- * Resolves the field on the given source object. In particular, this
- * figures out the value that the field returns by calling its resolve function,
- * then calls completeValue to complete promises, serialize scalars, or execute
- * the sub-selection-set for objects.
- */
+// Resolves the field on the given source object. In particular, this
+// figures out the value that the field returns by calling its resolve function,
+// then calls completeValue to complete promises, serialize scalars, or execute
+// the sub-selection-set for objects.
 func resolveField(eCtx *ExecutionContext, parentType *Object, source interface{}, fieldASTs []*ast.Field) (result interface{}, resultState resolveFieldResultState) {
 	// catch panic from resolveFn
 	var returnType Output
@@ -771,15 +768,13 @@ func defaultResolveFn(p ResolveParams) (interface{}, error) {
 	return nil, nil
 }
 
-/**
- * This method looks up the field on the given type defintion.
- * It has special casing for the two introspection fields, __schema
- * and __typename. __typename is special because it can always be
- * queried as a field, even in situations where no other fields
- * are allowed, like on a Union. __schema could get automatically
- * added to the query type, but that would require mutating type
- * definitions, which would cause issues.
- */
+// This method looks up the field on the given type defintion.
+// It has special casing for the two introspection fields, __schema
+// and __typename. __typename is special because it can always be
+// queried as a field, even in situations where no other fields
+// are allowed, like on a Union. __schema could get automatically
+// added to the query type, but that would require mutating type
+// definitions, which would cause issues.
 func getFieldDef(schema Schema, parentType *Object, fieldName string) *FieldDefinition {
 
 	if parentType == nil {