Move dependencies to stable version

gradle.properties

@@ -1,7 +1,7 @@
 org.gradle.caching=true
 group=org.ballerinalang
 version=1.2.0-alpha5-SNAPSHOT
-ballerinaLangVersion=2.0.0-alpha6-SNAPSHOT
+ballerinaLangVersion=2.0.0-alpha6
 ballerinaTomlParserVersion=1.2.2
 commonsLang3Version=3.8.1
 nettyVersion=4.1.50.Final
@@ -18,18 +18,18 @@ unirestVersion=1.4.9
 mimepullVersion=1.9.11
 testngVersion=6.14.3
 
-stdlibIoVersion=0.6.0-alpha5-SNAPSHOT
-stdlibHttpVersion=1.1.0-alpha5-SNAPSHOT
-stdlibRegexVersion=0.7.0-alpha5-SNAPSHOT
-stdlibOsVersion=0.8.0-alpha5-SNAPSHOT
-stdlibTimeVersion=2.0.0-alpha5-SNAPSHOT
-stdlibTaskVersion=2.0.0-alpha5-SNAPSHOT
-stdlibFileVersion=0.7.0-alpha5-SNAPSHOT
-stdlibCryptoVersion=1.1.0-alpha5-SNAPSHOT
-stdlibLogVersion=1.1.0-alpha5-SNAPSHOT
-stdlibMimeVersion=1.1.0-alpha5-SNAPSHOT
-stdlibCacheVersion=2.1.0-alpha5-SNAPSHOT
-stdlibAuthVersion=1.1.0-alpha5-SNAPSHOT
-stdlibJwtVersion=1.1.0-alpha5-SNAPSHOT
-stdlibOAuth2Version=1.1.0-alpha5-SNAPSHOT
-stdlibUuidVersion=0.10.0-alpha5-SNAPSHOT
+stdlibIoVersion=0.6.0-alpha5
+stdlibHttpVersion=1.1.0-alpha5
+stdlibRegexVersion=0.7.0-alpha5
+stdlibOsVersion=0.8.0-alpha5
+stdlibTimeVersion=2.0.0-alpha5
+stdlibTaskVersion=2.0.0-alpha5
+stdlibFileVersion=0.7.0-alpha5
+stdlibCryptoVersion=1.1.0-alpha5
+stdlibLogVersion=1.1.0-alpha5
+stdlibMimeVersion=1.1.0-alpha5
+stdlibCacheVersion=2.1.0-alpha5
+stdlibAuthVersion=1.1.0-alpha5
+stdlibJwtVersion=1.1.0-alpha5
+stdlibOAuth2Version=1.1.0-alpha5
+stdlibUuidVersion=0.10.0-alpha5