Add missing library to compilation example

[rendon]

Issue #, if available:

Description of changes: The example to compile standalone C++ programs is missing a library (-laws-crt-cpp), at least on Ubuntu.

The next snippet shows what happens when you run the command provided in the README.

$ g++ -o string string.cpp -std=c++11 -lcrypto -laws-encryption-sdk
 -laws-encryption-sdk-cpp -laws-c-common -laws-cpp-sdk-kms -laws-cpp-sdk-core
/usr/bin/ld: /tmp/cciWoA8n.o: undefined reference to symbol '_ZN3Aws3Crt11g_allocatorE'
//usr/local/lib/libaws-crt-cpp.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

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[texastony]

Howdy rendon,

Thank you for bringing up this compilation issue.

Could you help me recreate the compile error you encountered by replying with the commands you used to install the dependencies and the Encryption SDK (ESDK) for C? What versions did you install?

I am curious if you installed the entire AWS SDK for C or just the KMS portion. Did you install aws-c-common separately from the SDK?

Much Obliged,
AWS Crypto Tools

[rendon]

Cool, thanks guys!