Highlight dependencies which were removed in 2.1 (#5569)

* Highlight dependencies which were removed in 2.1

* Add libicu60 for Ubuntu Bionic Beaver

Author: kasper3

docs/core/linux-prerequisites.md

@@ -60,30 +60,37 @@ The following are intended to be examples. The exact versions and names may vary
 
 Ubuntu distributions require the following libraries installed:
 
-* libunwind8
 * liblttng-ust0
 * libcurl3
 * libssl1.0.0
-* libuuid1
 * libkrb5-3
 * zlib1g
 * libicu52 (for 14.x)
 * libicu55 (for 16.x)
 * libicu57 (for 17.x)
+* libicu60 (for 18.x)
+
+For versions earlier than .NET Core 2.1, following dependencies are also required:
+
+* libunwind8
+* libuuid1
 
 ### CentOS
 
 CentOS distributions require the following libraries installed:
 
-* libunwind
 * lttng-ust
 * libcurl
 * openssl-libs
-* libuuid
 * krb5-libs
 * libicu
 * zlib
 
+For versions earlier than .NET Core 2.1, following dependencies are also required:
+
+* libunwind
+* libuuid
+
 For more information about the dependencies, see [Self-contained Linux applications](https://github.com/dotnet/core/blob/master/Documentation/self-contained-linux-apps.md).
 
 ## Installing .NET Core dependencies with the native installers
@@ -428,4 +435,4 @@ To install .NET Core 2.x for supported SUSE Linux Enterprise Server and OpenSUSE
 > * [.NET Core 2.1 known issues](https://github.com/dotnet/core/tree/master/release-notes/2.1)
 > * [.NET Core 2.0 known issues](https://github.com/dotnet/core/tree/master/release-notes/2.0)
 > * [.NET Core 1.1 known issues](https://github.com/dotnet/core/blob/master/release-notes/1.1)
-> * [.NET Core 1.0 known issues](https://github.com/dotnet/core/blob/master/release-notes/1.0)
+> * [.NET Core 1.0 known issues](https://github.com/dotnet/core/blob/master/release-notes/1.0)