Fix not honoring indent after inline text

Lexer was silently ignoring indent after a tag with inline text
Now :

```
li foo
  span bar
```

throw an error and give you the solution

lib/index.js

@@ -2,7 +2,7 @@ const lex = require('./lexer')
 const parse = require('./parser')
 
 module.exports = function SugarMLParser(input, options) {
-  return parse(lex(input, options))
+  return parse(lex(input, options),input,options)
 }
 
 module.exports.lex = lex

lib/parser.js

@@ -2,11 +2,11 @@ const SugarmlError = require('./error')
 
 // Our target output is a reshape AST
 // (https://github.com/reshape/reshape#reshape-ast)
-module.exports = tokens => {
+module.exports = (tokens,input,options={}) => {
   let current = 0
   let indentLevel = 0
   let token = tokens[current]
-
+  
   function walk(ctx) {
     token = tokens[current]
 
@@ -151,9 +151,42 @@ module.exports = tokens => {
       // searching for contents
       const currentIndent = indentLevel
 
+      var forbiddenChildren=false
+      var inlineText=''
+      //If next token is 'text', we must not have child tokens
+      if (token && token.type==='text'){
+        inlineText = token.value; //Remember inline text value for futur use (in case of error)
+        node.content.push(walk(node.content)) //Get text
+        forbiddenChildren=true
+      }
+
       // now we recurse to get the contents, looping while the indent level is
       // greater than that of the current node, to pick up everything nested
       node.content.push(walk(node.content))
+      if (forbiddenChildren && indentLevel > currentIndent){
+        let errorLine
+        if (token){
+          errorLine = tokens[current-2].line; //With other token to parse, error line is 2 tokens before
+        }else{
+          errorLine = tokens[current-1].line; //Without anymore tokens to parse, error is on the last line
+        }
+        //Compute the awaited input
+        let splited = input.split('\n') //Split input line by line
+        let regex = inlineText.replace(/[.*+?^${}()|[\]\\]/g, '\\$&') + '$'; //Make regex from inlineText
+        let firstLine = splited[errorLine - 2].replace(new RegExp(regex),'') //Remove inlineText from first Error line
+        let thirdLine = splited[errorLine - 1] //Second line become third
+        let secondLine = thirdLine.match(/^\s+/)[0] + '| ' + inlineText //Second line is *pipe* + inlineText we removed on first error line
+        let shouldBe = `  1 | ${firstLine}\n  2 | ${secondLine}\n  3 | ${thirdLine}\n` //Pretty output
+        throw new SugarmlError({
+          message: `Inline text and nested tags cannot both be used at the same time. To resolve this error format your template as :\n\n${shouldBe}`,
+          location: {
+            filename: options.filename,
+            line: errorLine,
+            col: 0,
+            src: input
+          }
+        })
+      }
       while (indentLevel > currentIndent) {
         // eslint-disable-line
         node.content.push(walk(node.content))

test/fixtures/inline-text-nested-tag.sgr

@@ -0,0 +1,2 @@
+li foo
+  span bar

test/index.js

@@ -103,6 +103,12 @@ test('sugarml own comments', t => {
   return compare(t, 'sugarml-comments')
 })
 
+test('invalid nested tag after inline text error', t => {
+  return error('inline-text-nested-tag', t).catch(err => {
+    t.regex(err.toString(), /Inline text and nested tags cannot both be used at the same time. To resolve this error format your template as :\n\n  1 | li \n  2 |   | foo\n  3 |   span bar/)
+  })
+})
+
 function compare(t, name, log) {
   let html, expected