Replace jackson-core with vendored minimal-json

This commit removes our dependency on jackson-core and replaces it with
a vendored and slightly modified version of minimal-json. Reducing
dependencies on popular projects like Jackson make it easier to use
Smithy in large, heterogenous environments like large corporate build
systems. minimal-json is vendored into smithy-model to allow Nodes to be
parsed and serialized from JSON documents. The major change that was
added to minimal-json was to allow skipping over optional "//" line
comments.

NOTICE

@@ -7,6 +7,11 @@ THIRD PARTY COMPONENTS
 
 This software includes third party software subject to the following copyrights.
 
+minimal-json
+Copyright (c) 2013, 2014 EclipseSource
+https://github.com/ralfstx/minimal-json/blob/master/LICENSE
+
+
 Apache Commons Text
 Copyright 2014-2018 The Apache Software Foundation
 

config/checkstyle/suppressions.xml

@@ -18,6 +18,9 @@
         "-//Puppy Crawl//DTD Suppressions 1.1//EN"
         "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
 <suppressions>
+    <!-- Ignore "vendored" internal classes that have a different copyright. -->
+    <suppress checks="RegexpHeader" files="internal/*"/>
+
     <suppress checks="EqualsHashCode" files="shapes/*"/>
     <suppress checks="InnerAssignment" files="StringUtils"/>
     <suppress checks="TypeName" files="AwsJson1_0Trait.java|AwsJson1_1Trait.java"/>

smithy-build/src/test/java/software/amazon/smithy/build/FileManifestTest.java

@@ -88,7 +88,7 @@ public void writesJsonFiles() throws IOException {
 
         assertThat(Files.isDirectory(outputDirectory.resolve("foo")), is(true));
         assertThat(Files.isRegularFile(outputDirectory.resolve("foo/file.json")), is(true));
-        assertThat(new String(Files.readAllBytes(outputDirectory.resolve("foo/file.json"))), equalTo("{ }\n"));
+        assertThat(new String(Files.readAllBytes(outputDirectory.resolve("foo/file.json"))), equalTo("{}\n"));
     }
 
     @Test

smithy-build/src/test/java/software/amazon/smithy/build/model/SmithyBuildConfigTest.java

@@ -50,7 +50,7 @@ public void throwsWithCorrectSyntaxErrorMessage() {
             SmithyBuildConfig.load(Paths.get(getResourcePath("bad-syntax.json")));
         });
 
-        assertThat(thrown.getMessage(), containsString("Error parsing file"));
+        assertThat(thrown.getMessage(), containsString("Error parsing"));
     }
 
     @Test

smithy-model/build.gradle.kts

@@ -20,5 +20,4 @@ extra["moduleName"] = "software.amazon.smithy.model"
 
 dependencies {
     api(project(":smithy-utils"))
-    implementation("com.fasterxml.jackson.core:jackson-core:2.9.8")
 }